Question

Find the measure of the exterior angle.

Answer 1

Answer:

1) 128°

2) 126°

3) 108°

Question one:

   The square in the corner means 90°. If you add the interior angles of any triangle together, you get 180. in this case, x is in exterior angle, so you subtract it from 180 to get the interior angle.  

38 + 90 + (180-x) = 180

38 + 90 + 180 - x = 180

38 + 90 + 180 - 180 - x = 0

38 + 90 + 180 - 180 = x

128 = x

Question two:

again, adding all the interior angles makes 180°. use this to make the equation.

3x + (5x-6) + 90 = 180

3x + 5x - 6 = 90

8x = 96

x = 12.

   x isn't the answer the question wants, however. if you look at the drawing, the angle that's supplementary to 5x-6 is the exterior angle. so,

180 - (5x-6) = the answer

180 - 5x + 6 = the answer

substitute x for 12

180 - 60 + 6 = the answer

126 = x

Question three

again, adding all the interior angles together makes 180°.

(a + 10) + 44 + (180-2a) = 180

a + 10 + 44 + 180 - 2a = 180

-a + 234 = 180

234 - 180 = a

54 = a

however, the question is looking for the exterior angle, not a. in this case, the exterior angle is 2a, so just multiply 54 by 2.

x = 108