Question

question 18 pl explain​

Answer 1

Hey Pretty Stranger!

$\large \bold \red{Here \: you \: go \: !}$

$\textbf{\underline{\underline{Given:}}}$

• Perimeter of Semi-Circle is 108 cm

$\textbf{\underline{\underline{To\:Find:}}}$

• Diameter of the circle

$\textbf{\underline{\underline{Solution:}}}$

Let radius of the semi-circle be r

According to the Question :

$\star \sf \: \dfrac{1}{2}(2\pi \: r) + 2r = 108$

$\implies \sf \: \pi \: r + 2r = 108$

$\implies \sf \: \dfrac{22}{7} \times r + 2r = 108$

$\implies \sf \: 36 \: r = 108 \times 7$

$\implies \sf \: r = \large \boxed{ \red{ \sf \: 21 \: cm}}$

Diameter = 2 × Radius

Diameter = 2 × 21 = 42 cm

Answer 2

Answer:

★Diameter of Semicircle will be 42 cm★

Step-by-step explanation:

Given:

• Perimeter of SemiCircle is 108cm

To find: Diameter of the Semicircle

Solution:

★Let the perimeter of Semicircle be r cm

Therefore, Perimeter of Semicircle= 2r+πr

$\small\implies{\sf }$ (2+π)r

$\small\implies{\sf }$ (2+22/7) x r

$\small\implies{\sf }$ { (14+22/7) } x r

$\small\implies{\sf }$ So, Perimeter= 36r/7 .........(1)

Now, A/q

Given Perimeter is 108 cm.........(2)

• From equation (1) and (2) we have,

$\small\implies{\sf }$ 36r/7 = 108

$\small\implies{\sf }$ r= 108 x 7 /36

$\small\implies{\sf }$ r = 3 x 7 = 21 cm

So, Diameter of Semicircle will be 2r = 2 x 21 = 42 cm