One of the legs a right triangle is twice as long as the other and the perimeter of the triangle is 28. Find the lengths of all three sides, to three decimal places

So x 2x are the sides using Pythagorean theorem x^2 + (2x) ^2 = 5x^2

So the side is the square root of 5x^2 so now we have the third side

The sum of the sides should add to 28 so:

X+2x+√5x=28 factor the x

X (3+√5) = 28 and we know √5=2.236

So x = 28/5.236 = 5.347