Chapter 4.3, Problem 13PSB

To determine

To Prove: Supplement of a right angle is a right angle.

Explanation of Solution

Given information: right angle $\angle ABC.$

Formula used: Supplement of an angle $x^{\circ }$ is ${(180-x)}^{\circ }$ .

Proof:

  

  $\begin{array}{l}\angle ABC={90}^{\circ }(\text{measure}\text{of}\text{right}\text{angle}\text{is}{\text{90}}^{\circ })\\ \text{then}\text{supplement}\text{of}\angle ABCis{180}^{\circ }-\angle ABC\\ ={180}^{\circ }-{90}^{\circ }\\ ={90}^{\circ }\text{which}\text{is}\text{right}\text{angle}\text{.}\end{array}$