
The perimeter of a quadrant of a circle of radius $\dfrac{7}{2}cm$ is :
(a) $3.5cm$
(b) $5.5cm$
(c) $7.5cm$
(d) $12.5cm$
Answer
484.5k+ views
Hint:As we know that Circumference of circle is $2\pi r$ . Perimeter implies that the circumference of a circle and quadrant of a circle means one-fourth part of the circle. Using this concept we will get the required solution .
Complete step-by-step answer:
As We learn that Perimeter of the circle is $2\pi r$.
But in this question we have to find the perimeter of a quadrant of circle means that one-fourth of the perimeter of circle
Here we see that the blue colored part is the quadrant of the circle .
Perimeter of quadrant of circle is $\dfrac{{2\pi r}}{4}$
where we take $\pi = \dfrac{{22}}{7}$ and Radius of circle is given $r = \dfrac{7}{2}$ ;
By putting these value ,
= $\dfrac{{2 \times \dfrac{{22}}{7} \times \dfrac{7}{2}}}{4}$
When we solve we get
= $\dfrac{{22}}{4}$$cm$
In decimal form
= $5.5cm$
So, the correct answer is “Option B”.
Note:Students should also remembered that Area of Circle is = $\pi {r^2}$ And the area of quadrant is $\dfrac{{\pi {r^2}}}{4}$.Perimeter of semi-circle is $\pi r$ and Area of semi-circle is $\dfrac{{\pi {r^2}}}{2}$.
Perimeter of Square is $4 \times a$ and Area of Square is ${a^2}$ where a is the side of the square.
Perimeter of rectangle is $2\left( {l + b} \right)$ and Area of rectangle is $l \times b$ where $l = $ Length of Rectangle and $b = $ breadth of Rectangle.
Complete step-by-step answer:
As We learn that Perimeter of the circle is $2\pi r$.
But in this question we have to find the perimeter of a quadrant of circle means that one-fourth of the perimeter of circle
Here we see that the blue colored part is the quadrant of the circle .

Perimeter of quadrant of circle is $\dfrac{{2\pi r}}{4}$
where we take $\pi = \dfrac{{22}}{7}$ and Radius of circle is given $r = \dfrac{7}{2}$ ;
By putting these value ,
= $\dfrac{{2 \times \dfrac{{22}}{7} \times \dfrac{7}{2}}}{4}$
When we solve we get
= $\dfrac{{22}}{4}$$cm$
In decimal form
= $5.5cm$
So, the correct answer is “Option B”.
Note:Students should also remembered that Area of Circle is = $\pi {r^2}$ And the area of quadrant is $\dfrac{{\pi {r^2}}}{4}$.Perimeter of semi-circle is $\pi r$ and Area of semi-circle is $\dfrac{{\pi {r^2}}}{2}$.
Perimeter of Square is $4 \times a$ and Area of Square is ${a^2}$ where a is the side of the square.
Perimeter of rectangle is $2\left( {l + b} \right)$ and Area of rectangle is $l \times b$ where $l = $ Length of Rectangle and $b = $ breadth of Rectangle.
Recently Updated Pages
Master Class 9 General Knowledge: Engaging Questions & Answers for Success

Master Class 9 English: Engaging Questions & Answers for Success

Master Class 9 Science: Engaging Questions & Answers for Success

Master Class 9 Social Science: Engaging Questions & Answers for Success

Master Class 9 Maths: Engaging Questions & Answers for Success

Class 9 Question and Answer - Your Ultimate Solutions Guide

Trending doubts
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

How do you graph the function fx 4x class 9 maths CBSE

Name the states which share their boundary with Indias class 9 social science CBSE

Difference Between Plant Cell and Animal Cell

What is pollution? How many types of pollution? Define it

What is the color of ferrous sulphate crystals? How does this color change after heating? Name the products formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this type of change.
