In parallelogram ABCD, the measure of angle A is 99 degrees. Explain why the measure of adjacent angle B must be 81 degrees.

The measure of angle B must be 81° because angles A and B are interior supplementary angles

Step-by-step explanation:

Let us revise the properties of a parallelogram

In any parallelogram:

Let us solve our question

In parallelogram ABCD

∵ AD and BC are opposite sides

∴ AD // BC

∵ ∠A and ∠B are adjacent angles

→ That means ∠A and ∠B are interior supplementary angles

∴ ∠A and ∠B are supplementary angles

∵ The sum of the measures of the supplementary angles is 180°

∴ m∠A + m∠B = 180°

∵ m∠A = 99°

∴ 99° + m∠B = 180°

→ Subtract 99° from both sides

∴ 99° - 99° + m∠B = 180° - 99°

∴ m∠B = 81°

The measure of angle B must be 81° because angles A and B are interior supplementary angles

i would say the third one.

step-by-step explanation: liner would mean in a line and the only one that doesn't look like it's even thinking about forming a line would be the third one