After finding the ratio between two line in a triangle...?

Question

can you use that ratio to find the length of the last side of the triangle... i know you can use pythag. therom. but can you just use the ratio to??

Answer 1

No. You could have a triangle with two sides of lengths 3 and 4. But the last side could just as easily be length 2 as length 6.

Answer 2

You didn't say if it's a right triangle. If it is, then pythagoras is the only quick solution that gives a correct answer. If not a right triangle, then you have a trickier problem!