Question

the sides of a triangle shaped sheet are 5cm. 12cm. 13cm. find the cost of painting on the sheet at the rate of 30 per cm

Answer 1

s=12+5+13/2
15
root over s(s-a)(s-b)(s-c)
3*5*2*5*3*2
30cm²
1cm²=30
30cm²=900ruppees

Answer 2

S = A+B+C/2

S = 5 + 12 + 13/2

S = 30/2 = 15

$area \: = \: \sqrt{s(s - a)(s - b)(s - c)}$
$\sqrt{15(15 - 5)(15 - 12)(15 - 13)}$
$\sqrt{15 \times 10 \times 3 \times 2}$
$\sqrt{5 \times 3 \times 5 \times 2 \times 3 \times 2}$
$\sqrt{900}$
= 30 Sq. cm

Cost of painting = 30 × 30

= 900 Rs