**Define Sphere**

Sphere is the one type of three dimensional geometrical objects.Surface area is an total amount of outer area of a three dimensional sphere.

A sphere is a perfectly round geometrical object. It is a three dimensional shape. The volume and surface **area of sphere** can be calculated easily if radius is given. The
volume of sphere is expressed in terms of cubic unit and area of sphere is expressed in terms of **square unit**. In this article we are going to see about surface area and volume of
sphere with example problems.

**Surface area of the sphere (A) = 4 **π r^{2 }square unit

**A- Surface area.**

** r- Radius**

**Volume of a sphere (v) = `4/3` **π r ^{3 }cubic unit

** V-volume**

** r- Radius**

** Ex 1: ****The sphere has radius of 3.5cm. Find the surface area and volume of sphere.**

**Sol:**

Given:

Radius (r) = 3.5 cm

Formula:

**Surface area of the sphere (A) = 4 **π r^{2 }square unit

**A- Surface area.**

** r- Radius**

** ** Substitute the r value in the formula and simplify,

**
** = 4 x π x 3.5^{2}

=4 x π x 12.25

** ****Surface area of the sphere
(A)**** =**** ****153.86 cm ^{2}**

**Volume of the sphere (v) = `4/3` π r ^{3 }cubic unit**

** **V-volume

r- Radius

** ** Substitute the r value in the formula and simplify,

** **
= `4/3` x π x (3.5)^{3}

=`4/3` x 3.14 x 42.875

** ****Volume of the sphere (v)****
=** **179.503 cm ^{3}**

**Ex 2: ****The sphere has radius of 7m. Find the surface area and volume of sphere.**

**Sol:**

Given:

Radius (r) = 7m

Formula:

**Surface area of the sphere (A) = 4 **π r^{2 }square unit

**A- Surface area.**

** r- Radius**

** ** Substitute the r value in the formula and simplify,

= 4 x π x 7^{2}

=4 x π x 49

** ****Surface area of the sphere
(A)**** =**** 615.44****m ^{2}**

**Volume of the sphere (v) = `4/3` π r ^{3 }cubic unit**

** **V-volume

r- Radius

** ** Substitute the r value in the formula and simplify,

= `4/3` x π x (7)^{3}

=`4/3` x 3.14 x 343

** ****Volume of the sphere (v)****
=** 1436.02 **m ^{3}**

**Ex 3: Find the surface area of a sphere whose radius 4cm?**

**Sol:**

Given:

r = 4cm

Surface area of cone = 4πr^{2}

= 4 ×3.14× 4^{2}^{ }

= 4 ×3.14× 16

= 200.96cm^{2}

**Ex 4: ****Find the surface area of a sphere whose radius 6cm?**

**Sol:**

Given:

r = 6cm

Surface area of cone = 4πr^{2}

= 4 ×3.14× 6^{2}^{ }

= 4 ×3.14× 36

= 452cm^{2}

**Practice problems:**

1. The sphere has radius of 5.7m. Find the surface area and volume of sphere.

**Ans:**

Surface area (A) = 408.28137 m^{2}

Volume (V) = 775.7346 m^{3}

2. The sphere has radius of 6.5cm. Find the surface area and volume of sphere.

**Ans:**

Surface area (A) = 530.92 cm^{2}

Volume (V) = 1150.3466 cm^{3}

3. The sphere has radius of 9.3cm. Find the surface area and volume of sphere.

**Ans:**

Surface area (A) = 1086.8654 cm^{2}

Volume (V) = 3369.2827 cm^{3}

3) Find the surface area of a sphere whose radius 7cm?

**Ans: ** 615cm^{2}

4) Find the surface area of a sphere whose radius 9m?

**Ans:** 1017m^{2}