Respuesta :
Answer:
18 inches
Step-by-step explanation:
The median of a trapezoid is the average of the lengths of the bases.
15 + 21 = 36
36 ÷ 2 = 18
good luck, i hope this helps :)
Answer:
18 inches
Step-by-step explanation:
Refer to this link:
https://brainly.com/question/7564799