Martin S. answered 04/04/20
Patient, Relaxed PhD Molecular Biologist for Science and Math Tutoring
From the Pythagorean theorem we know that a2 + b2 = c2.
We also know that one side is 15 feet and the hypotenuse is twice the length of the other side, So let's make a = 15 feet, then the hypotenuse becomes 2b (twice the length of the other side).
So now rewrite the equation by substituting for a and c, and a2 + b2 = c2. becomes:
152 + b2 = (2b)2 , or 225 + b2 = 4b2
subtract b2 from both sides, giving 225 = 3b2
Next, divide by 3, and we have 75 = b,
Take the square root of both sides to get the length of side b, and b = 5√3.
The hypotenuse is twice the length of side b, so c = 10√3.
To check, plug the values back into the Pythagorean theorem:
152 + (5√3)2 = (10√3)2
225 + 75 = 300, check.