Math, asked by hkohli, 9 months ago

11. An isosceles triangle has perimeter 30 cm and each of the equal sides is 12 cm. Find
the area of the triangle.​

Answers

Answered by ashigupta9935456176
2

Step-by-step explanation:

let the third side of the triangle be x

perimeter is equals to sum of all sides so 12 + 12 + x is equals to 30 X is equals to 30 - 24 is equals to 6 as the the third side is 6 according to the formula of finding the area of triangle 1 upon 2 base into height base is equals to 6 and height is equals to 12 show the the area of the equilateral triangle is 36 CM square.

I hope it helps plz mark me brainliest friend

Answered by BlessedMess
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}

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