Chapter 3, Problem 32CUR

To determine

To state: the postulate or theorem which justifies the given statement, “If $\overline{DA}\perp \overline{AB}$ , then $m\angle DAB=90$ ”

Answer to Problem 32CUR

Explanation of Solution

Given:

The diagram:

Concept Used:

Perpendicular Lines: Two lines which intersect each other to form right angle $\left(90°\right)$ are called perpendicular lines.

Consider the given figure:

It is given that $\overline{DA}\perp \overline{AB}$ , that is $\overline{DA}$ and $\overline{AB}$ are perpendicular lines.

Then, by definition of perpendicular lines, $\overline{DA}$ and $\overline{AB}$ intersect each other at right angles.

So,

  $m\angle DAB=90$