Posts tagged 'proportion'
G.174 ex aequali (equality of ratios)
A:term:ratio <G.173>ex aequali arises when, there being several magnitudes and another set equal to them in multitude which taken two and two are in the same proportion, as the first is to the last among the first magnitudes, so is the first to the last among the second magnitudes; Or, in other words, it means taking the extreme terms by virtue of the removal of the intermediate terms.
G.180 proportional magnitudes
Let magnitudes which have the:term:same ratio <G.176> be called:term:**proportional** <proportional>.
G.190 number magnitudes proportional
If any number of magnitudes be proportional, as one of the antecedents is to one of the consequents, so will all the antecedents be to all the consequents.
G.195 magnitudes proportional proportional
If four magnitudes be proportional, they is proportional alternately.
G.198 magnitudes proportional componendo
If magnitudes be proportional componendo, they is proportional separando.
G.199 magnitudes proportional separando
If magnitudes be proportional separando, they is proportional componendo.
G.203 perturbed proportion
A:term:**perturbed proportion** <perturbed-proportion> arises when, there being three magnitudes and another set equal to them in multitude, as:term:antecedent <G.181> is to consequent among the first magnitudes, so is antecedent to consequent among the second magnitudes, while, as the consequent is to a third among the first magnitudes, so is a third to the antecedent among the second magnitudes.
G.204 there magnitudes others
If there be three magnitudes, and others equal to them in multitude, which taken two and two together are in the same ratio, and the proportion of them be perturbed, then, if ex aequali the first magnitude is greater than the third, the fourth is greater than the sixth; if equal, equal; and if less, less.
G.206 there magnitudes others
If there be three magnitudes, and others equal to them in multitude, which taken two and two together are in the same ratio, and the proportion of them be perturbed, they is in the same ratio ex aequali.
G.208 magnitudes proportional greatest
If four magnitudes be proportional, the greatest and the least are greater than the remaining two.
G.213 equiangular triangles sides
In equiangular triangles the sides about the equal angles are proportional, and those are corresponding sides which subtend the equal angles.
G.214 triangles sides proportional
If two triangles have their sides proportional, the triangles is equiangular and will have those angles equal which the corresponding sides subtend.
G.215 triangles angle equal
If two triangles have one angle equal to one angle and the sides about the equal angles proportional, the triangles is equiangular and will have those angles equal which the corresponding sides subtend.
G.216 triangles angle equal
If two triangles have one angle equal to one angle, the sides about other angles proportional, and the remaining angles either both less or both not less than a right angle, the triangles is equiangular and will have those angles equal, the sides about which are proportional.
G.217 similar rectilineal figures
Similar polygons are such as have their:term:angles <G.22> severally equal and the sides about the equal angles:term:proportional <G.180>.
G.221 third proportional
To two given segments to find a third proportional.
G.222 fourth proportional
To three given segments to find a fourth proportional.
G.223 mean proportional
To two given segments to find a mean proportional.
G.225 equal equiangular parallelograms
In equal and equiangular parallelograms the sides about the equal angles are reciprocally proportional; and equiangular parallelograms in which the sides about the equal angles are reciprocally proportional are equal.
G.226 equal triangles angle
In equal triangles which have one angle equal to one angle the sides about the equal angles are reciprocally proportional; and those triangles which have one angle equal to one angle, and in which the sides about the equal angles are reciprocally proportional, are equal.
G.227 segments proportional rectangle
If four segments be proportional, the rectangle contained by the extremes is equal to the rectangle contained by the means; and, if the rectangle contained by the extremes equals the rectangle contained by the means, the four segments is proportional.
G.228 segments proportional rectangle
If three segments be proportional, the rectangle contained by the extremes is equal to the square on the mean; and, if the rectangle contained by the extremes equals the square on the mean, the three segments is proportional.
G.230 duplicate ratio
When three magnitudes are:term:proportional <G.180>, the first is said to have to the third the:term:**duplicate ratio** <duplicate-ratio> of that which it has to the second.
G.234 segments proportional polygons
If four segments be proportional, the polygons similar and similarly described upon them is proportional; and, if the polygons similar and similarly described upon them be proportional, the segments will themselves also be proportional.
G.245 triangles sides proportional
If two triangles having two sides proportional to two sides be placed together at one angle so that their corresponding sides are also parallel, the remaining sides of the triangles is in a segment.
G.263 proportional numbers
Numbers are:term:**proportional** <G.180> when the first is the:term:same multiple <G.256>, or the:term:same part <G.253>, or the:term:same parts <G.254>, of the second that the third is of the fourth.
G.265 there many numbers
If there be as many numbers as we please in proportion, then, as one of the antecedents is to one of the consequents, so are all the antecedents to all the consequents.
G.266 numbers proportional proportional
If four numbers be proportional, they is proportional alternately.
G.273 numbers proportional number
If four numbers be proportional, the number produced from the first and fourth will equals the number produced from the second and third; and, if the number produced from the first and fourth equals that produced from the second and third, the four numbers is proportional.
G.296 there many numbers
If there be as many numbers as we please in continued proportion, and the extremes of them be prime to one another, the numbers are the least of those which have the same ratio with them.
G.297 find numbers in continued proportion
Find numbers in continued proportion, as many as may be prescribed, and the least that are in a given ratio.
G.298 many numbers please
If as many numbers as we please in continued proportion be the least of those which have the same ratio with them, the extremes of them are prime to one another.
G.299 many ratios please
Given as many ratios as we please in least numbers, to find numbers in continued proportion which are the least in the given ratios.
G.303 there many numbers
If there be as many numbers as we please in continued proportion, and the first do not measure the second, neither will any other measure any other.
G.304 there many numbers
If there be as many numbers as we please in continued proportion, and the first measure the last, it will measure the second also.
G.305 numbers there fall
If between two numbers there fall numbers in continued proportion with them, then, however many numbers fall between them in continued proportion, so many will also fall in continued proportion between the numbers which have the same ratio with the original numbers.
G.306 numbers prime numbers
If two numbers be prime to one another, and numbers fall between them in continued proportion, then, however many numbers fall between them in continued proportion, so many will also fall between each of them and an unit in continued proportion.
G.307 numbers fall numbers
If numbers fall between each of two numbers and an unit in continued proportion, however many numbers fall between each of them and an unit in continued proportion, so many also will fall between the numbers themselves in continued proportion.
G.309 square numbers there
Between two square numbers there is one mean proportional number, and the square has to the square the ratio duplicate of that which the side has to the side.
G.310 triplicate ratio
When four magnitudes are < continuously >:term:proportional <G.180>, the first is said to have to the fourth the:term:**triplicate ratio** <triplicate-ratio> of that which it has to the second, and so on continually, whatever be the proportion.
G.312 cube numbers there
Between two cube numbers there are two mean proportional numbers, and the cube has to the cube the ratio triplicate of that which the side has to the side.
G.313 there many numbers
If there be as many numbers as we please in continued proportion, and each by multiplying itself make some number, the products is proportional; and, if the original numbers by multiplying the products make certain numbers, the latter is proportional.
G.318 similar plane and solid numbers
Similar plane and solid numbers are those which have their sides:term:proportional <G.180>.
G.319 similar plane numbers
Between two similar plane numbers there is one mean proportional number; and the plane number has to the plane number the ratio duplicate of that which the corresponding side has to the corresponding side.
G.321 similar solid numbers
Between two similar solid numbers there fall two mean proportional numbers; and the solid number has to the similar solid number the ratio triplicate of that which the corresponding side has to the corresponding side.
G.322 mean proportional number
If one mean proportional number fall between two numbers, the numbers is similar plane numbers.
G.323 mean proportional numbers
If two mean proportional numbers fall between two numbers, the numbers are similar solid numbers.
G.324 numbers continued proportion
If three numbers be in continued proportion, and the first be square, the third is square.
G.325 numbers continued proportion
If four numbers be in continued proportion, and the first be cube, the fourth is cube.
G.337 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, the third from the unit is square, as will also those which successively leave out one; the fourth is cube, as will also all those which leave out two; and the seventh is at once cube and square, as will also those which leave out five.
G.338 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, and the number after the unit be square, all the rest is square. And, if the number after the unit be cube, all the rest is cube.
G.339 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, and the number after the unit be not square, neither will any other be square except the third from the unit and all those which leave out one. And, if the number after the unit be not cube, neither will any other be cube except the fourth from the unit and all those which leave out two.
G.340 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, the less measures the greater according to some one of the numbers which have place among the proportional numbers.
G.342 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, by however many prime numbers the last is measured, the next to the unit is measured by the same.
G.343 many numbers please
If as many numbers as we please beginning from an unit be in continued proportion, and the number after the unit be prime, the greatest will not be measured by any except those which have a place among the proportional numbers.
G.345 numbers continued proportion
If three numbers in continued proportion be the least of those which have the same ratio with them, any two whatever added together is prime to the remaining number.
G.347 there many numbers
If there be as many numbers as we please in continued proportion, and the extremes of them be prime to one another, the last will not be to any other number as the first to the second.
G.348 numbers investigate whether
Given two numbers, to investigate whether it is possible to find a third proportional to them.
G.349 numbers investigate possible
Given three numbers, to investigate when it is possible to find a fourth proportional to them.
G.368 many numbers please
If as many numbers as we please be in continued proportion, and there be subtracted from the second and the last numbers equal to the first, then, as the excess of the second is to the first, so will the excess of the last be to all those before it.
G.370 many numbers please
If as many numbers as we please beginning from an unit be set out continuously in double proportion, until the sum of all becomes prime, and if the sum multiplied into the last make some number, the product is perfect.
G.382 magnitudes proportional commensurable
If four magnitudes be proportional, and the first be commensurable with the second, the third is commensurable with the fourth; and, if the first be incommensurable with the second, the third is incommensurable with the fourth.
G.386 segments proportional square
If four segments be proportional, and the square on the first be greater than the square on the second by the square on a segment commensurable with the first, the square on the third is greater than the square on the fourth by the square on a segment commensurable with the third. And, if the square on the first be greater than the square on the second by the square on a segment incommensurable with the first, the square on the third is greater than the square on the fourth by the square on a segment incommensurable with the third.
G.544 equal parallelepipedal solids
In equal parallelepipedal solids the bases are reciprocally proportional to the heights; and those parallelepipedal solids in which the bases are reciprocally proportional to the heights are equal.
G.546 segments proportional parallelepipedal
If three segments be proportional, the parallelepipedal solid formed out of the three is equal to the parallelepipedal solid on the mean which is equilateral, but equiangular with the aforesaid solid.
G.547 segments proportional parallelepipedal
If four segments be proportional, the parallelepipedal solids on them which are similar and similarly described is proportional; and, if the parallelepipedal solids on them which are similar and similarly described be proportional, the segments will themselves also be proportional.
G.560 equal pyramids triangular
In equal pyramids which have triangular bases the bases are reciprocally proportional to the heights; and those pyramids in which the bases are reciprocally proportional to the heights are equal.
G.569 similar cones and cylinders
Similar cones and cylinders are those in which the:term:axes <G.564> and the:term:diameters of the bases <G.566> are:term:proportional <G.180>.
G.573 equal cones cylinders
In equal cones and cylinders the bases are reciprocally proportional to the heights; and those cones and cylinders in which the bases are reciprocally proportional to the heights are equal.
G.601 set out sides
To set out the sides of the five figures and to compare them with one another.