Question

An isosceles triangle has perimeter 30cm and each of the equal to equal sides is 12 centimetre find its area of triangle

Answer 1

As we know that two sides of Isosceles triangle are equal,
So,

First Side = 12 cm
Second Side = 12 cm
Then,
Let third side = x cm

As we know that sum of all sides = Perimeter

=> 12+12+ x = 30 cm
=> x = 30-24 cm
=> x = 6 cm

Now,

=> S = P/2
=> S = 30/2 = 15 cm


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

$= > \: a \: = \sqrt{15(15 - 12)(15 - 12)(15 - 6)}$

$= > \: a = \sqrt{15 \times 3 \times 3 \times 9}$

$= > \: a = \sqrt{5 \times 3 \times 3 \times 3 \times 3 \times 3} {cm}^{2}$
$= > \: a = 9 \sqrt{15} {cm}^{2}$



Be Brainly

Answer 2

hey

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third side be x

x+12+12=30

x=30-24

x=6

•by using heron's formula

s=a+b+c/2

s=12+12+6/2

s=30/2

s=15

area =√s(s-a)(s-b)(s-c)

area=√15(15-12)(15-12)(15-6)

area=√15×3×3×9

area=√3×5×3×3×3×3

area=9√15

hope helped

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