Question

20. The edges of a triangular board are 6 cm, 8 cm and 10 cm. The cost of painting it at the rate
of 9 paisa per cm² is
(A) Rs 2.00
(B) Rs 2.16
(C) Rs 2.48
(D) Rs 3.00​

Answer 1

Area of triangle:

S = (6 + 8 + 10)/ 2 = 12

Area = √S (S-S1) (S-S2) (S-S3)

= √(12×6×4×2)

= √576

= 24 cm²

Cost of Painting = 24 × 0.09 = Rs. 2.16

Answer 2

tell me He paints the outer walls of the model shed at the rate of 20 paisa per cm2

. Then the cost of painting will be

a) Rs.400

b) Rs.450

c) Rs.500

d) Rs.610