First let me give you the formula
A= (b1+b2)/2 X h OR A= 1/2h (b1+b2)
i will use the second one ^^^
A= 1/2h (b1+b2)
now plug in the Numbers:
84=1/2h(28)
the next step is to multiply 28 by 1/2
28/2=14
You are left with:
84=14h
divide both sides of the equation by 14
you get:
84/14=6
So h=6
to check the problem simply plug in the numbers:
84=1/2(6) (28) multiply 6*28=168
84=1/2(168)
84=84
If you have any questions you can e-mail me at Southqueensb@yahoo.com
~EVY~