Question

A rhombus sheet, whose perimeter is 32 m and whose one diagonal is 10 m long, is painted on both sides at the rate of Rs. 5 per m². Find the cost of painting.

Answer 1

Answer:

let ABCD BE RHOMBUS

perimeter of rhombus = 4*AB

32=4*AB

AB=32m

In ΔABE

By pythagorus thm

AB²=AE²+BE²

8²=5²+EB²

⇒EB²=39

EB=√39

⇒BD=2√39                                                  (              BD=2EB          )

AREA OF RHOMBUS = 1/2 * d1 * d2

=1/2 * 10 * 2√3

= 10√39

area of painted side = 2 * 10√39

=20√39m²

rate = rupees 5 m²

cost of painting = 20√39 * 5

= 100 * 6.245

=rupees 624.5