Question

please refer attachment and answer






from R.D Sharma




class 10​

Answer 1

Given :-

θ = 60

Radius = 7 cm

To Find :-

Perimeter

Solution :-

We know that

$\sf Diameter=2\times r$

$\sf Diameter=2\times 7$

$\sf Diameter=14\;cm$

$\sf Perimeter=\dfrac{\theta}{360}\times 2\pi r+D$

$\sf \dashrightarrow Perimeter=\dfrac{60}{360}\times 2\times \dfrac{22}{7}\times 7+14$

$\sf \dashrightarrow Perimeter =\dfrac{1}{6}\times \dfrac{44}{7}\times 7+14$

$\sf \dashrightarrow Perimeter=\dfrac{1}{6}\times 44+14$

$\sf \dashrightarrow Perimeter=\dfrac{22}{3}+14$

$\sf \dashrightarrow Perimeter =\dfrac{22+42}{3}$

$\sf \dashrightarrow Perimeter=\dfrac{64}{3}$

Option A is correct

Answer 2

Answer:

A} 64/3

Step-by-step explanation:

Q 21.] The perimeter of the sector OAB figure in the attachment  is ________.

ans]

    Given that,

    Radius(r)= 7cm

    Theta(∅)= 60°

Perimeter of the sector ,P = length of the arc, AB + radius, OA + radius, OB

Here, theta is the angle given in the figure.

P = θ/360° × 2πr + r + r  

P = θ/360° × 2πr + 2 r  

P = 60°/360° × 2 × π× 7 + 2 × 7  

P = ⅙× 14 × 22/7 + 14  

P = 44/6 + 14

P = 22/3 + 14

P = (22 + 42)/3

P = 64/3 cm

Perimeter of the sector, OAB = 64/3 cm

Hence, the perimeter of the sector , OAB is 64/3 cm .

HOPE THIS ANSWER WILL HELP YOU….