Question

BAC= 90 dgrees. The lenght of the three sides are xcm, (x=7) and x+8)cm.
a. Write down and simplify a quadratic equation in x which links the three sides of the triangle.
b. Solve the quadratic equation found in part (a)
c. Write down the value of the perimeter of the triangle.

Answer 1

If you do not say which side is the hypotenuse (opposite the right angle), I can not help you.
hypotenuse^2 = side^2 + other side^2

Answer 2

x^2 + (x+7)^2 = (x+8)^2
solve for x, or save yourself some time by memorizing a few basic tripes, such as 5-12-13