SOLUTION: one leg of a right triangle is twice as long as the other leg. the length of the hypotenuse is 20 squared. what is the length of each leg

Algebra ->  Triangles -> SOLUTION: one leg of a right triangle is twice as long as the other leg. the length of the hypotenuse is 20 squared. what is the length of each leg      Log On


   



Question 423229: one leg of a right triangle is twice as long as the other leg. the length of the hypotenuse is 20 squared. what is the length of each leg
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
Assume the legs are a, b, and c.
c = the hypotenuse.
c = 20^2
c = 400
.
One leg is twice as long as the other.
a = 2b
.
The Pythagorean Theorem teaches us:
c^2 = a^2 + b^2
.
Substituting what we know...
400^2 = (2b)^2 + b^2
160000 = 4b^2 + b^2
160000 = 5b^2
Divide both side by 5.
32000 = b^2
Take the square root of both sides.
sqrt(32000) = b
.
sqrt(32 000) = 178.885438
so
b = 178.885438
.
Looking back, we see that
a = 2b
so
a = 2 * 178.885438
a = 357.770876
.
Always check your answer.
In this case you do so by checking to see if c^2 = a^2 + b^2.
Is this equation true?
a^2 = 128,000
b^2 = 32,000
a^2 + b^2 = 160,000
That checks.
.
Remember to state the answer clearly.
The legs of the right triangle are 178.885438 and 357.770876.
.
Done.