Question

find the area of the triangle two sides are 5cm and 12cm and perimeter 30cm

Answer 1

perimeter is the sum of all the sides..
thus the third side = 30-12-5 = 13 cm
using heron's formula, we can find the area..
area=
$\sqrt{(s \div 2)(s - a)(s - b)(s - c)}$
here s is the semi perimeter
s= 30/2 =15
$\sqrt{15 \times (15 - 12)(15 - 5)(15 - 13)}$
$\sqrt{15 \times 3 \times 10 \times 2}$
30 cm