Question

for safety and strength, the supports of a set of scissor steps form parallelograms. what should the measure of ∠1 be to allow a dog to climb safely into its owner’s car?

corresponding angles theorem,
same - side interior angles postulate,
alternate - exterior angles theorem,
alternate interior angles theorem,

the angles at the top right of the parallelograms in the arm are \boxed{congruent} because they are \boxed{corresponding angles}. by the \boxed{same - side interior angles postulate}, ∠1 is \boxed{congruent} to these angles, so m∠1 = \boxed{99} (do not include the degree symbol in your answer.)

Explanation:

Step1: Identify Angle Relationship

In a parallelogram, using the Same - Side Interior Angles Postulate (or properties of parallel lines in the parallelogram structure), we know the relationship between ∠1 and the given angle (implied to be 99° from the problem's context as the angles are congruent or related in a way that ∠1 equals 99°).

Step2: Determine Measure of ∠1

Since the angles are congruent (as per the reasoning about corresponding angles and the postulate), the measure of ∠1 is equal to 99.

Answer:

99