Monique and her dad built a hang glider together. After testing the new glider for safety, the glider was ready for the first big flight. Monique jumped off a tall sand dune and traveled in a diagonal line from the top of the dune toward the ground. She flew for 137 feet and landed on level ground at a spot 105 feet horizontally from where she took off. How tall was the sand dune

answers are
a. -88 ft
b. 88 ft
c. 173 ft
d.cannot be determined