Chapter 2.5, Problem 6WE

To determine

To state: The theorem that justifies about statement of the diagram

Answer to Problem 6WE

The theorem is:

if two lines makes angle of ${90}^{\circ }$ then lines are said to be perpendicular and vice versa.

Explanation of Solution

Given information:

  

  $\overline{BE}\perp \overrightarrow{AC}$ then $\angle ABD$ and $\angle DBE$ is complementary angle.

If $\overline{BE}\perp \overrightarrow{AC}$ then $\angle ABD$ and $\angle DBE$ is complementary angle

The theorem is:

if two lines makes angle of ${90}^{\circ }$ then lines are said to be perpendicular and vice versa.

Hence, $m\angle ABD+m\angle DBE=90$