Question

the lenght of a median of a trapezoid is 7 units the lenght of a longer base is 21 units how long is the shorter base

Answer 1

how can i solve it...?

Answer 2

I think using the formula @waterineyes gave you in the previous post:
\[\text{Length Of Median} = \frac{1}{2} \times (\text{Sum Of Length Of Bases)}\]

Answer 3

Here you are given :

\[7 = \frac{1}{2} \times (21 + x)\]

Find x here, that is your Length of Shorter Base..

Answer 4

waterineyes: m=b1+b2/2 can be this formula