Question

If two angles of a triangle have measures of 42° and 20°, what is the measure of the

third?
128°
118°
98°
108°

Answer 1

118

Explanation:

We know,

Sum of all angles of triangle is 180 degree.

Let, the third angle be x,

or, 42 + 20 + x = 180

or, 62 + x = 180

or, x = 180 - 62 = 118

Therefore, the third angle is 118 degrees

Answer 2

118°

Explanation:

the angle measures of a triangle will always add up to 180

so..

42+20=62

180-62=118