Chapter 4.2, Problem 67SR

To determine

The property that justifies each statement.

Answer to Problem 67SR

Substitution Property.

Explanation of Solution

Given:

The given statement is:

  $Ifm\angle 1+m\angle 22=90\text{ and m}\angle 2\text{ = m}\angle 3\text{, then m}\angle 1\text{ + m}\angle 3=90.$

Calculation:

Substitute

If $m\angle 3\text{ for m}\angle 2$ in $m\angle 1+\text{m}\angle 2=90$ ;

Therefore,

  $m\angle 1+m\angle 3=90$

Hence, the property used is Substitution Property.