Find the length of a side of a square whose diagonal is 3 cm longer than a side.

Question

Solve and type an equation

Answer 1

Let s = the length of a side of the square

Let s + 3 = the length of the diagonal of the square

Use the Pythagorean Theorem.

s² + s² = (s + 3)²

2s² = s² + 6s + 9

s² - 6s - 9 = 0

Use the quadratic formula.

s = 6 ±√[36 + 36]

              2

s = 6 ±√72

          2

s = 6 ± 6√2

          2

s = 3 ± 3√2