Chapter E, Problem 3.2EX

To determine

To Find:

The measure of $\angle DEB$ .

Answer to Problem 3.2EX

The measure of $\angle DEB$ is option (b) ${40}^{\circ }$ .

Explanation of Solution

Given information:

If $m\angle ABE=40$ in the given figure.

If $m\angle ABE=40$ , then by the property of sum of the angles.

  $\begin{array}{l}100+40+x=180\\ x=40\end{array}$

Therefore, the measure of $\angle DEB$ is option (b) ${40}^{\circ }$ .