Question

What is the value of H?

Answer 1

The formula of an area of a tringle:

$A_\Delta=\dfrac{base\cdot height}{2}$

We have:

$b_1=20\ ft,\ h_1=12\ ft$

and

$b_2=30\ ft,\ h_2=h$

The area does not change. Therefore we have the equation:

$\dfrac{(30)(h)}{2}=\dfrac{(20)(12)}{2}\\\\15h=(10)(12)\\\\15h=120\qquad|:15\\\\\boxed{h=8\ ft}$