Question

Find the area of a triangle in which too side are 8cm and 6cm and the perimeter is 18cm

Answer 1

Answer:

a+b+c= 18

14+c=18

c=4

s=a+b+c/2=9

area=√s(s_a)(s-b)(s-c)

√9×1×3×5

√135cm²

Answer 2

let the 3rd side be x

let the 3rd side be xperimeter = 18

8 + 6 + + x = 18

x = 4 cm

$s = \frac{18}{2} = 9 \\ area = \sqrt{9(9 - 8)(9 - 4)(9 - 6) } \\ = \sqrt{9 \times 1 \times 5 \times 3} \\ = 3 \sqrt{15} \: {cm}^{2}$