Question

find the area of isosceles triangle whose each
of equal side is 15em and the perimeter
is n 42​

Answer 1

Answer:

15+15+x = 42

30+x = 42

x = 42-30

x = 12

using heron's formula

s= 42÷2

s = 21

$\sqrt{21 \times (21 - 15) \times (21 - 15)(21 - 12)}$

$\sqrt{21 \times 6 \times 6 \times 9}$

$\sqrt{7 \times 3 \times 2 \times 3 \times 2 \times 3 \times 3 \times 3}$

$2 \times 3 \times 3 \sqrt{7 \times 3}$

$18 \sqrt{21}$

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