#1**+2 **

So, let's do the first problem!

If \(RG'\) is 12 and\(G'G\) is 3, then \(RG\) is 15 because \(12+3=15\) .

\(RG'/RG = 12/15 = 4/5\)

Therefore, the scale factor is 4/5, or C.

Second problem.

Why would you need an altitude, AAS Congruence, or any similar triangles? All you need is substitution in the Pythagorean Theorem, or answer A.

Third problem!

The triangles are similar, so we set up the ratio \(18/y=10.8/18\) and cross-multiplying we get \(324=10.8y\).

Simplifying for \(y \) we get \(y=30\) so the answer is D.

You are very welcome!

:P

CoolStuffYT
Nov 7, 2018

#2**+1 **

The answer to the second one is "B"....this will divide the larger right triangle into two smaller similar right triangles which can be used to prove the P Theorem

For the last one......we have this relationship

y - 10.8 14.4

______ = ______ cross-multiply

14.4 10.8

10.8 ( y - 10.8) = 14.4 * 14.4

10.8 y - 116.64 = 207.36 add 116.64 to both sides

10. 8 y = 324 divide both sides by 10.8

y = 30

CPhill
Nov 7, 2018