Question

1. (l19) given: ad ⊥ cb prove: ∠dob is a right angle a. if the exterior sides of a pair of adjacent angles are perpendicular, then the angles are complementary. b. transitive property c. reflexive property d. a right angle is an angle with a measure of 90. e. perpendicular lines intersect to form four right angles.

Explanation:

Step1: Recall perpendicular - angle relationship

If two lines are perpendicular, the angles formed are right angles. Given \(AD\perp CB\), the intersection of the lines creates right - angled situations.

Step2: Analyze adjacent angles formed by perpendicular lines

When the exterior sides of a pair of adjacent angles are perpendicular, the angles are complementary. Complementary angles add up to 90 degrees. In the case of perpendicular lines \(AD\) and \(CB\), if \(\angle DOB\) is formed at the intersection, and the exterior sides of adjacent angles related to the perpendicular lines are considered, the adjacent angles are complementary.

Answer:

A. complementary.