A rhombus shaped sheet with perimeter 40 cm and one diagonal is 12 cm, is painted on both sides at the rate of rs.5 per m sq. find the cost of painting. need the answer fast. pls help

let ABCD be a rhombus,

perimeter = 40

so, AB=BC=CD=DA=10

let diagnols ACBD intersect at O

so let BD =12

or BO=6so in trangle AOB

AB²= AO²+OB²

AO²=10²-6²

AO²=64

AO=8

AC=16

so area of rhombus is 1/2*d₁*d₂

ar ABCD = 1/2*12*16

=96cm²

total area of both sides = 192 cm²

cost of painting 1 m² = Rs 5

cost of painting 10000 cm² = Rs 5       (1m sq = 10,000 cm sq)

cost of painting 1 cm² = Rs 5/10000

cost of painting 192 cm² = Rs 5/10000 * 192

cost of painting 192 cm² = Re 0.096

it will cost 9.6 paise for painting both the sides of rhombus