use the triangle sum theorem to determine the measure of the third angle in each triangular circuit. Label the triangles with the unknown angle measures

Question

Carnegie Learninight analyzing angles and sides 

Answer 1

The sum of the angles = 180 degrees for any triangle

IF you know two of the angles, say angle A and angle B

then subtract them from 180 to get the 3rd angle C

C = 180-A-B

For example, if A=20 and B= 50 then C= 180-20-50 = 110 degrees