Chapter 2.1, Problem 7CE

To determine

To state: the hypothesis and the conclusion combining exercise 5 and 6.

Answer to Problem 7CE

  $\angle 1\cong \angle 2$ if and only if $m\angle 1=m\angle 2$ .

Explanation of Solution

Given information:

  $\angle 1\cong \angle 2$ if $m\angle 1=m\angle 2$ and $\angle 1\cong \angle 2$ only if $m\angle 1=m\angle 2$ .

Calculation:

We have : $\angle 1\cong \angle 2$ if $m\angle 1=m\angle 2$ and

  $\angle 1\cong \angle 2$ only if $m\angle 1=m\angle 2$ .

Combining both we get $\angle 1\cong \angle 2$ if and only if $m\angle 1=m\angle 2$ .