Hi!
The equation to find the area of a triangle is...
(a = area
b = base
h = height)
[tex]a = \frac{1}{2} bh[/tex]
Fill in the values that we already have.
[tex]861 = \frac{1}{2}82*h[/tex]
Divide both sides by 1/2
[tex]861/ \frac{1}{2} = \frac{1}{2}/ \frac{1}{2}82*h[/tex]
1722 = 82*h
Divide both sides by 82.
1722/82 = 82/82*h
21 = h
The answer is B. 21 cm
Hope this helps! :)
