Question

find the area of an isoceles triangle whose sides are 12 cm ,12 cm,6 cm and perimetre is 30cmusing heron's formula class 9th​

Answer 1

$area \: of \: triangle = \sqrt{s(s - a)(s - b)(s - c)}$

Step-by-step explanation:

perimeter=30

s=15

$area = \sqrt{15(15 - 12)(15 - 12)(15 - 6)}$

$= \sqrt{15 \times 3 \times 3 \times 9}$

$= 3 \times 3 \sqrt{15}$

$= 9 \sqrt{15}$