Question 661169
you need to know the length of one of the sides.
otherwise, you will have 1 equation in 2 unknowns which can't be solved for a single value but can be solved for a multiple number of values if you assume a number for one for one of them.
example:
triangle is a right triangle with a hypotenuse of 18.
the pythatogean formula says that a^2 + b^2 = c^2 where a and b are legs and c is the hypotenuse.
square the 18 to get 324
your equation now becomes a^2 + b^2 = 324
you can solve for a in terms of b or you can solve for b in terms of a but you can't solve for a or b directly because you have 1 equation with 2 unknowns.


if you assume a value for a, then you can find a value for b.
if you assume a value for b, then  you can find a value for a.


let's assume that a is equal to 8.
this means that a^2 = 64 and the equation becomes:
64 + b^2 = 324
subtract 64 from both sides of the equation to get b^2 = 324 - 64 which becomes b^2 = 260.
take the square root of both sides of that equation to get b = sqrt(260).


you have a = 8 and b = sqrt(260).
to find the hypotenuse use the pythagorean formula again to get:
a^2 + b^2 = c^2 which becomes:
8^ + sqrt(260)^2 = 18^2
simplify to get 64 + 260 = 324
combine like terms to get 324 = 324
the equation is true so a = 8 and b = sqrt(260) is a solution to the equation.


to get this solution, you had to assume a = 8.
if you are given the value of one of the legs and the hypotenuse, then you can solve for the other leg.