Question

an isosceles triangle has perimeter 30 cm and each of the equal side is 12cm. find the area of the triangle​

Answer 1

Answer:

here is your answer mate....

Step-by-step explanation:

Let The Third Side Be X cm.

Now Perimeter = 12+12+x

24+x = 30

x = 6

Using Herons Formula

S=a+b+c/2

  =12+12+6/2

   =30/2

  S =15 cm

Sq Root(15(15-12)(15-12)(15-6) ) = Sq Root(15*3*3*9) = Sq Root(1215) = 34.85 cm^2

So Area is 34.85cm^2

please mark it as brainliest.....

Answer 2

First,let the third side be x.

It is given that the length of the equal sides us 12 cm and it's perimeter is 30 cm.

So,$30=12+12+x$

$⇒ 30 = 24 + x$

$⇒24 + x = 30$

$⇒ x= 30 - 24$

$⇒ x = 6$

So,the length of the third side is 6 cm.

Thus,the semi perimeter of the isosceles triangle (s) = 30/2 cm =15 cm

By using Heron's Formula,

Area of the triangle,

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

$= \sqrt{15(15 - 12)(15 - 12)(15 - 6)} \: {cm}^{2}$

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

$= 9 \sqrt{15} \: {cm}^{2}$