Question

A=1/2h(B+b); A=21, B=2, b=4 h= ?

Answer 1

h=7

21=1/2h(2+4)
21=1/2h(6)
6/2=3
21/3=7

Answer 2

Explanation:

21=.5h(2+4)

21=.5h(6)

21=3h

/3 /3

7=h

21=.5(7)(6)

21=.5(42)

21=21