Chapter 3.4, Problem 21WE

To determine

The value of $m\angle C$

Answer to Problem 21WE

Angle value of angle $m\angle C>{60}^0$

Explanation of Solution

Given :

  $m\angle A={60}^0\text{ and }m\angle B<{60}^0$

According to property of triangle sum of angles of a triangle is ${180}^0$

Therefore,

  $m\angle A+m\angle B+m\angle C={180}^0$

For, $m\angle B<{60}^0$

  $\begin{array}{l}m\angle A+m\angle B+m\angle C>{180}^0\\ {60}^0+{60}^0+m\angle C>{180}^0\\ {120}^0+m\angle C>{180}^0\\ m\angle C>{60}^0\end{array}$

Therefore, angle $m\angle C>{60}^0$