College

A right triangle's height is 4 times the length of its base. If the area of the triangle is 800, what is the height?

A. 79
B. 83
C. 80
D. 84
E. 20
F. 77

Answer :

Sure! Let's solve the problem step by step.

We are given a right triangle where the height is 4 times the length of the base and the area of the triangle is 800. We need to find the height.

1. Let the length of the base be [tex]\( b \)[/tex].
2. Thus, the height [tex]\( h \)[/tex] is [tex]\( 4b \)[/tex] (since the height is 4 times the base).

3. The formula for the area of a triangle is:
[tex]\[
\text{Area} = \frac{1}{2} \times \text{base} \times \text{height}
\][/tex]

4. Substitute the known values into the formula:
[tex]\[
800 = \frac{1}{2} \times b \times 4b
\][/tex]

5. Simplify the equation:
[tex]\[
800 = 2b^2
\][/tex]

6. Solve for [tex]\( b^2 \)[/tex]:
[tex]\[
b^2 = \frac{800}{2} = 400
\][/tex]

7. Take the square root of both sides to solve for [tex]\( b \)[/tex]:
[tex]\[
b = \sqrt{400} = 20
\][/tex]

8. Since the height [tex]\( h \)[/tex] is 4 times the base:
[tex]\[
h = 4 \times b = 4 \times 20 = 80
\][/tex]

So, the height of the triangle is [tex]\(\boxed{80}\)[/tex].