Question

the area of semicircular field is 77 cm square find it perimeter plz say answer if u know I should write now plz answer step by step​

Answer 1

Given:

• Area of semicircular field = 77 cm²

To find:

• Perimeter of semicircular field?

Solution:

According to the given Question:

Area of semicircular field = 77 cm²

⇏ πr²/2 = 77

⇏ 22/7 × r² = 77 × 2

⇏ 22/7 × r² = 154

⇏ r² = 154 × 7/22

⇏ r² = 49

⇏ √r² = √49

⇏ r = 7 cm

Now, Finding area of semicircular field,

⇏ 2πr/2 + 2r

⇏ πr + 2r

⇏ 22/7 × 7 + 2 × 7

⇏ 22 + 14

⇏ 36 cm

∴ Hence, perimeter of semicircular field is 36 cm.

Answer 2

Given ,

The area of semi circular field is 77 cm²

We know that , the area of semi circle is given by

$\boxed{ \tt{Area = \frac{\pi {(r)}^{2} }{2} }}$

Thus ,

$\tt 77 = \frac{22 \times {(r)}^{2} }{7 \times 2}$

$1078 = 22 \times {(r)}^{2}$

${(r)}^{2} = 49$

$r = \pm \: 7 \: \: cm$

Since , the length can't be negative

Therefore , the radius of semi circle is 7 cm

Now , the perimeter of semi circle is given by

$\boxed{ \tt{Perimeter = \pi r + 2r}}$

Thus ,

Perimeter = 22/7 × 7 + 2 × 7

Perimeter = 22 + 14 cm

Therefore , the perimeter of semi circle is 36 cm

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