Chapter 6.4, Problem 5E

To determine

To find: $m\angle B$

Answer to Problem 5E

Thevalue of $m\angle B=90°$ .

Explanation of Solution

Given information: From the diagram provided in the problem, $\Delta ABC\sim \Delta DEF$ .

The angle is determined as,

In triangle ABC and DEF

  $\begin{array}{l}\angle B=90°\\ \angle A=90°\end{array}$

Since, triangles ABC and DEF are similar

Therefore,

  $\begin{array}{l}m\angle B=90°\\ m\angle A=90°\\ m\angle B=m\angle A\end{array}$

Therefore the answer is $m\angle B=90°$