Question

Find the measure of the indicated angle in each triangle.A=86B=133C=47D=180

Answer 1

The sum of the internal angles of a triangle is 180°. Therefore:

$m\angle E+m\angle F+m\angle G=180$

Solving for m∠F:

$\begin{gathered} 47+m\angle F+86=180 \\ 133+m\angle F=180 \end{gathered}$

Subtract 133 on both sides:

$\begin{gathered} 133+m\angle F-133=180-133 \\ m\angle F=47 \end{gathered}$

Answer: C. 47°