Question

a rhombus sheet whose perimeter is 40 m and whose one diagonal is 12m and is painted on both sides at rate of rs 5 per m sq. find cost of painting

Answer 1

p=40m
side =p/4
=10m
d=12m=AC
therefore , half of lt= 6m
we know that the diagonals of the bisect each other at 90°.
therefore in ∆AOB,angle AOB=90°.
by Pythagoras therom,
OB=8m
therefore BD=2×OB
=16m
now, area= 1/2×d1×d2
=1/2×16×12
=96metre square.
cost of 1m square=₹5
therefore, cost of 96m square=₹96×5
=₹480 Ans.