Two angles of a triangle measure 12º and 40°. What is the measure of the third angle of the triangle?
A. 38°
B. 48°
C. 128°
D. 308

12+40= 52

180-52=128

Step-by-step explanation:

Angles in a triangle add up to 180

so if two sides are given , they must be added and subtracted from 180.

which gives us 180-52=128

the angle is 128°

the right answer is C

Step-by-step explanation:

the angles of a triangle are always 180°

thus

the angle of the the triangle = 180° - (12°+40°)

= 180- 52° = 128°