Area of a rhombus is 840 square cm. Side of the rhombus is 29 cm. What is the sum (in cm) of its diagonals?
Show answer & explanation
Correct answer: A
Explanation
Area of the rhombus = 1/2 × d₁ × d₂
840 = 1/2 × d₁ × d₂
d₁ × d₂ = 1680
Side = 29 cm
(d₁/2)² + (d₂/2)² = 29²
d₁² + d₂² = 4 × 841
= 3364
(d₁ + d₂)² = d₁² + d₂² + 2d₁d₂
= 3364 + 3360
= 6724
d₁ + d₂ = √6724 = 82 cm