Question

a rhombus whose perimeter is 32 M and whose one diagonal 10 M long is painted on both side on the rate of Rs 5 per M find the cost of paint

Answer 1

Perimeter of the rhombus = 32 m 
Length of each side = a = 32/4 m = 8 m 
Length of one diagonal = d1 = 10m 
Length of the other diagonal = d2 
(d1/2)² + (d2/2)² = a² 
=> (10/2)² + (d2/2)² = 8² 
=> 25 + (d2/2)² = 64 
=> (d2/2)² = 64 - 25 = 39 
=> d2/2 = √39 
=> d2 = 2√39 m 
Area of the rhombus = A = (1/2)d1*d2 
= (1/2)*10*2√39 m² = 10√39 m² =10*6.245 m² = 62.45² m² 
Area of both the sides = 2A = 2*62.45 m² = 124.90 m² 
Cost of painting = Rs124.90 * 5 = Rs 624.50

Answer 2

the answer of this question is 625.50