SOLUTION: My question for homework is: Find the value of x for which (x + 2) cm, (2x + 3) cm and (2x + 5) cm are the three sides of a right-angled triangle. I have already tried to add a

Algebra ->  Triangles -> SOLUTION: My question for homework is: Find the value of x for which (x + 2) cm, (2x + 3) cm and (2x + 5) cm are the three sides of a right-angled triangle. I have already tried to add a      Log On


   



Question 901335: My question for homework is:
Find the value of x for which (x + 2) cm, (2x + 3) cm and (2x + 5) cm are the three sides of a right-angled triangle.
I have already tried to add all of the sides together but then I realized there was nothing i could put as the total. As well as this I have already tried to times all of the sides together and that didn't really work either. I'm quite confused and was wondering if you could help, thank you!

Found 2 solutions by richwmiller, ewatrrr:
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
It is a right triangle!
a^2+b^2=c^2 where c is the hypotenuse (the longest side)
Here the longest side is 2x+5
(x+2)^2+(2x+3)^2=(2x+5)^2

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
Pythagorean Theorem: a^2 + b^2 = c^2
(x+2)^2 + (2x+3)^2 = (2x+5)^2 solve for x
5x^2 + 16x + 13 = 4x^2 + 20x + 25
x^2 -4x - 12 = 0
(x-6)(x+2) = 0 (Tossing out the negative solution for unit measure)
x = 6checking...
64 + 225 = 289