SOLUTION: I need some help on this problem please: find out the length of sides a & b on the following triangle. A=x, b=3x and c = 19. I think I should use the pythagorean theorem. I squa

Algebra ->  Customizable Word Problem Solvers  -> Geometry -> SOLUTION: I need some help on this problem please: find out the length of sides a & b on the following triangle. A=x, b=3x and c = 19. I think I should use the pythagorean theorem. I squa      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 132345: I need some help on this problem please: find out the length of sides a & b on the following triangle. A=x, b=3x and c = 19. I think I should use the pythagorean theorem. I squared 19 to get 361, but I don't know how to figure the rest. Any advice would be great.
Found 2 solutions by solver91311, checkley71:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!
You don't say, and I certainly can't see the figure, but I'll just assume that you have a right triangle and that side c is the hypotenuse. Given those assumptions, the Pythagorean Theorem is the correct approach to the solution.

We know that a%5E2%2Bb%5E2=c%5E2, so let's substitute the given values and see where it takes us.

x%5E2%2B%283x%29%5E2=19%5E2

x%5E2%2B9x%5E2=19%5E2

10x%5E2=19%5E2

x%5E2=19%5E2%2F10

x=sqrt%2819%5E2%2F10%29=sqrt%2819%5E2%29%2Fsqrt%2810%29=19%2Fsqrt%2810%29

19%2Fsqrt%2810%29 is certainly an answer to the problem, but it is not in simplest terms because of the radical in the denominator. Simplest terms demands that, if possible, the denominator must be a rational number.

So, we need to perform a process called rationalizing the denominator. In this case, all we need to do is multiply 19%2Fsqrt%2810%29 by 1 in the form of sqrt%2810%29%2Fsqrt%2810%29

%2819%2Fsqrt%2810%29%29%28sqrt%2810%29%2Fsqrt%2810%29%29=19sqrt%2810%29%2F10. Final answer, Regis.

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
IF YOU HAVE A RIGHT TRIANGLE AND THE 19 SIDE IS THE HYPOTENUSE THEN YES USE THE PYTHAGOREN THERUM:
X^2+(3X)^2=19^2
X^2+9X^2=361
10X^2=361
X^2=361/10
X=SQRT36.1
X=6.008 ANSWER FIOR THE SHORTER SIDE.
X=3*6008
X=18.025 ANSWER FOR THE LONGER SIDE.
PROOF
6.008^2+18.025^2=19^2
36+325=361
361=361