Answer:
C. m∠A=40° and m∠B=140°
Step-by-step explanation:
We have been given that ∠A and ∠B are supplementary, Daisy conjectured that ∠A≅∠B. We are asked to find the counterexample to Daisy's conjecture.
We know that a counterexample is an example that contradicts an idea or theory.
Since ∠A and ∠B are supplementary, so they will add up-to 180 degrees.
Daisy conjectured that ∠A≅∠B, so the measure of angle A will be equal to measure of angle B.
This means that measure of angle A and B is 90 degrees.
The counterexample to Daisy's conjecture would be example that shows the measure of angle A and measure of angle B other than 90 degrees.
Upon looking at our given choices, we can see that option C shows that measure of angle A is 40 degrees and measure of angle B is 140 degrees, therefore, option C is a counterexample to Daisy's conjecture.