Question

NO ONE EVER HELPS ME , PLEASE HELP ME I NEED HELP!

If A=1/2 h (b1 +b2) is the formula for the area of a trapezoid, find the height of the trapezoid that has an area of 78 in ^2 and base lengths 5 in and 8 in.

Answer 1

A is the answer

12 in

first substitute the variables

then 78=1/2h(5 + 8)

this makes it an equation

add similar terms which equals to

78=1/2xhx13

then divide both sides by 13

6=1/2xh

lastly divide both sides by 1/2

12=h

Explanation:

proof

A=1/2x12(5 + 8) then

A=1/2x12x13 then

A=6x13 then

A= 78in^2