Question

an issocless triangle peremeter is 20cm each side is 7cm find area of it​

Answer 1

Question

An issosceles triangle , whose peremeter is 20cm, and equal side are 7cm . then find area oof this triangle.

Solution

Given :-

• Perimeter of issosceles triangle = 20 cm
• Equal side be (a ) = 7 cm

Find :-

• Area of issosceles triangle

Explaantion

Using Formula

★ Perimeter of triangle = Sum of all side.

★ Area of issosceles triangle = 1/2 × base × Height

Let,

• Base of isosceles triangle = v

First Calculate Base of this triangle

For this,

==> Perimeter of issosceles triangle = 20

==> 7 + 7 + b = 20

==> b = 20 - 14

==> b = 6 cm

Now, Calculate Height of issosceles triangle

Using Formula

★ Height = √[ a² - b²/4]

Keep Value

==> Height (h) = √[ 7² - 6²/4]

==> Height (h) = √[ 49 - 36/4]

==> Height (h) = √[ 49 - 9]

==> Height (h) = √40

==> Height (h) = 2√10 cm

Now, Calculate area

==> Area of issosceles triangle = 1/2 × Base × Height

keep Value,

==> Area of issosceles triangle = 1/2 × 6 × 2√10

==> Area of issosceles triangle = 6√10 cm²

Hence

• Area of issosceles triangle will be = 6√10 m²

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