Question

from a circular piece of cardboard of radius 3 cm, two sectors of 90° have been cut off. Find the perimeter of the remaining portion nearest hundredth cm​

Answer 1

Answer:

• 9.42 cm is the required Perimeter.

Step-by-step explanation:

Given:-.

• From a circular piece of cardboard of radius 3 cm, two sectors of 90° have been cut off.

To Find:-

• Perimeter of Remaining Portion

Solution:-

As we know that the sum of angles at centre in a circle is 360°

It is given that there are two sector of 90° cut off from the circle.

Therefore, angle cut off = 2×90° = 180

Remaining angle = 360° - 180° = 180°

As we know that the sum of angles in semicircle is 180° .

So, We have to calculate the Perimeter of Semicircle.

• Perimeter of Semicircle = πr

where,

• π denote = 22/7
• r denote radius.

Substitute the value we get

→ Perimeter of Semicircle = 22/7 × 3

→ Perimeter of Semicircle = 66/7

→ Perimeter of Semicircle = 9.42 cm

• Hence, the perimeter of remaining portion is 9.42 cm.

• Perimeter of remaining portion nearest hundredth is 9.00 cm.

Answer 2

Given :-

from a circular piece of cardboard of radius 3 cm, two sectors of 90° have been cut off

To Find :-

Perimeter

SoluTion :-

We are already aware of that sum of centre in a circle is 360⁰.

Angle cut off = (2)(90) = 180⁰

Remaining angle of circle = 360 - 180 = 180⁰

$\sf Perimeter \: of \: semicircle = \pi r$

$\sf Perimeter = \dfrac{22}{7} \times 3$

$\sf Perimeter \: = \dfrac{22 \times 3}{7}$

$\sf Perimeter = \dfrac{66}{7}$

$\huge \frak \red{Perimeter = 9.42 cm}$

Now,

Nearest Hundredth

9.42 or 9.4 cm