Using the pythagorean theorem how do you find the unknown lengths A=5x-1 B=x+2 C=5x?

1 Answer
Feb 13, 2016

Two solutions. The three lengths are either 3, 4 and 5 or 7, 24 and 25.

Explanation:

It is apparent in three sides of right angled triangle (as Pythagorean theorem is indicated) that among three sides A=5x-1, B=x+2 and C=5x, C is the largest. Applying Pythagoras theorem,

(5x-1)^2+(x+2)^2=5x^2 or

25x^2-10x+1+x^2+4x+4=25x^2 or

x^2-6x+5=0. Factorizing this, we get

(x-5)(x-1)=0 or x=5 or 1

Putting x=5, the three lengths are 24, 7, 25

and putting x=1, the three lengths are 4, 3, 5