In a triangle, the second angle is twice the measure of the first, and the third angle is three times the measure of the second. Find the measure of the third angle.

A. 20 degrees

B. 30 degrees

C. 120 degrees

D. 180 degrees

Question

In a triangle, the second angle is twice the measure of the first, and the third angle is three times the measure of the second. Find the measure of the third angle.

A. 20 degrees

B. 30 degrees

C. 120 degrees

D. 180 degrees

lacypennelll · Answer

http://www.algebra.com/algebra/homework/Angles/Angles.faq.question.227900.html try this hun ^-^

zehanz · Answer

Suppose the value of the first angle is called a.
The second is twice the first, so it's 2a.
The third is three times the second, so it's ....
Adding all three of them up gives: xxx times a = 180.
You now know a, so you can calculate the measure of the third angle!

anonymous · Answer

the equation would 2a + 3a = 180

zehanz · Answer

What about the first angle with measure a?

anonymous · Answer

6

zehanz · Answer

It is a + 2a + 3*(2a) = 180

anonymous · Answer

oh. so the rest would be 2a + 6a = 180

zehanz · Answer

In total: 9a = 180, so a = 20, so the measure of the third is...

anonymous · Answer

20

zehanz · Answer

No, that is a, the measure of the first one!
The third one is 6a = 6*20 = 120, so it is answer C.