Question

What is the measure of a?

Answer 1

The sum of angles of a triangle is 180 degrees.

`\begin{gathered} \angle A+\angle B+\angle C=180 \\ \angle A+43+15=180 \\ \angle A+58=180 \\ \angle A=180-58 \\ \angle A=122\text{ degr}ees \end{gathered}`

Thus, the vakue of a is 122 degrees.