Question

two measures of a triangle are 20 degrees and 40 degrees.what is the measure,in degrees,of the other angle?

Answer 1

Remember that the sum of the internal angles of every triangle is 180°.

Therefore, find an angle A such that:

$20+40+A=180$

Add 20+40:

$60+A=180$

Substract 60 from both sides to find the value of A:

$\begin{gathered} A=180-60 \\ =120 \end{gathered}$

Therefore, the measure of the remaining angle is 120°.