Answer:
14.4
Explanation:
since the longest side is 24,find the shortest side
√20^2-12^2
√400-144
√256
=16
which means the other shortest side is 24-16
which is 8
then you have to use the 12 and 8 to find the unknown side
√12^2+8^2
144+64
√208
14.4
I hope this helps