Question

What is the ratio of these two pentagons?

Answer 1

@KendrickLamar2014 Help me?

Answer 2

i got 12/28 but im not sure

Answer 3

@Ilovecake @forzamilan

Answer 4

@Secret-Ninja

Answer 5

@tester97

Answer 6

didnt i answer dis?

Answer 7

im not sure, i dont think i've seen it if you did

Answer 8

oh wait i didnt post it...:o

Answer 9

Thats okay, What did you say it was?

Answer 10

There are a few different formulas for finding the area of a pentagon. The one I recommend for this problem is

A=(sqrt(5(5+2*sqrt(5)))*a^2)/4

This is a big formula, but you could use it to find the areas. However, in this case we only want the ratio of the areas. That means that we will set up a fraction, plugging 12 into that equation for the numerator, and 28 into the bottom for the demoninator. The nice thing about doing it as a fraction means that all the constants will cancel out. that will leave just 12^2/28^2 as our ration. Simplifying this gives us:

12^2/28^2 = (12/28)^2 = (3/7)^2 = 9/49

Which is answer D of your choices.