Triangle Angle Sums

Triangle Angle Sums

Interior /Exterior Angles

A+M+T=180

27+82+?=180

27+82=109

180-109=71

Exterior Angles Theorem

The exterior angle of a triangle is equal to the two interior angles across from it.

So, to solve for x, you just do 75+36=111

IF you're looking for one of the interior angles, you have the subtract 110-80=30

Use algebra to solve.

x+x+2+38=180

2x+40=180

2x=140

x=70, so B=70, C=72

The exterior angle is equal to the 2 interior angles added. 5y+3+4y+8=146

9y+11=146

9y=135

y=15

Poll

How are you doing with triangle angles?

• I'm awes

• I'm ok

• I'm lost