Chapter 14.2, Problem 15PPS

To determine

To calculate angle of triangle

Answer to Problem 15PPS

52°,54° and 74°

Explanation of Solution

Given information:

Angles are $(x+15)°,(2x-20)°,2x$ °

Formula used :Angle sum property of triangle

Calculation:

According to angle sum property of triangle,

  $\angle A+\angle B+\angle C=180°$

Substituting values of angle,

  $\begin{array}{l}(x+15)°+(2x-20)°+2x=180°\\ 5x+15-20=180\\ 5x-5=180\\ 5x=185\\ x=\frac{185}{5}\\ x=37\end{array}$

Angles are :

  $\begin{array}{l}(x+15)°=(37+15)=52°\\ (2x-20)°=2(37)-20=74-20=54°\\ 2x=2\times 37=74°\end{array}$