Question

The diagonal of a square is 12 cm long.Find its perimeter and area

Answer 1

Area of square = 1/2 (d)²

= 1/2 (12)²

= 1/2 × 12 × 12

= 72

Side of a square = √Area

= √72

= √(2 × 2 × 2 × 3 × 3)

= 2 × 3√2

= 6 × 1.41

= 8.46 cm

Perimeter of square = 4 × 8.46 = 33.84 cm

Answer 2

Answer:

Let the side of the square =a cm.

The diagonal of a square divides it into two equal right angled triangles.

Hence, diagonal forms the hypotenuse of a right angled triangle, with the other

two sides being the sides of the square.

Hence, diagonal =

a

2

+a

2

=12cm=>2a

2

=144=>a

2

=72=>a=6

2

Area of the square =a

2

=(6

2

)

2

=72 sq cm