Question

The side of a square is 6 cm, what would be the square of it’s diagonal’s length?

(a) √72

(b) 36

(c) √36

(d) 72

This question was addressed to me in my homework.

This intriguing question originated from Quadrilaterals topic in section Quadrilaterals of Mathematics – Class 8

Answer 1

Right answer is (d) 72

To explain: As the diagonals of a square are perpendicular bisectors of each other, the form a right angles triangle. Here to find the length of the diagonal could be found by using Pythagoras Theorem.

∴ By Using Pythagoras Theorem we get,

∴ (6)^2 + (6)^2 = x^2

∴ 36+36=x^2

∴ 72=x^2