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Circle G and circle U are similar. Find the value of X

A.
5
B.
15
C.
60
D.
240

Circle G and circle U are similar. Find the value of X A. 5 B. 15 C. 60 D. 240-example-1
User ChenLee
by
6.6k points

2 Answers

3 votes
since they are similar, their radius:angles ratio will be the same so set up a proportion:

(20\pi)/(3) / 4\pi = (x)/(9) \\ crossmultiply \\ 4\pi * x = (20\pi)/(3) * (9)/(1)

4\pi * x = (20\pi)/(1) * (3)/(1) \\ 4\pi * x = 60\pi \\ (4\pi \: x)/(4\pi) = (60\pi)/(4\pi) \\ x = 15
B) 15 is your final answer
User Maxmaxmaximus
by
6.7k points
1 vote
Hello!

First you have to find what they did to get the second triangle

20 / 3 = 6.666...

6.666... / 4 = 1.666...

The multiplied the first circle by 1.666... to get the second circle

Multiply where x is in the first circle

9 * 1.6666 = 14.999

Round this to 15

The answer is B) 15

Hope this helps!
User Fernando Bessa
by
8.1k points