Question

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

Answer 1

Answer:

Can u send the length of the equal sides?

Answer 2

Correct Question:

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

Answer: 9$\sqrt{15}$ cm²

$\textbf{\underline{\underline{Step-by-step\: Explanation}}}$

$\sf\blue{Given:}$

• Two sides are equal.
• Perimeter = 30 cm

$\sf\green{To Find :}$

• Area of triangle

$\sf\pink{Assume :}$

• Let unknown sides be a, b and c

$\sf\blue{Formula\: used :}$

• Area of triangle = $\sqrt{s(s-a)(s-b)(s-c)}$

$\huge\mathscr\red{Solution :}$

→ First of all, find semi perimeter of the given triangle.

s = $\dfrac{perimeter}{2}$

 = $\dfrac{30}{2}$

= 15 cm

→ To find c

a + b + c = 30

⇒ 12 + 12 + c = 30

⇒ 24 + c = 30

⇒ c = 30 - 24

⇒ c = 6 cm

→ Finally, To find the area of triangle :

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

→ put the values in the given formula

we get,

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

= $\sqrt{15(3)(3)(9)}$

= $\sqrt{15(9)(9)$

= 9√15 cm²

Answer: Area of the given rectangle is 9√15 cm²