Curved Surface Area of a Hemisphere
The curved surface area of a hemisphere is the space occupied by the curved surface of the hemisphere. The surface area of a three-dimensional object is defined as the space occupied by the surface of the object. A hemisphere is obtained when a sphere is cut along a plane passing through the center of the sphere. In other words, a hemisphere is half of a sphere. In this section, we will discuss the curved surface area of a hemisphere along with solved examples.
What is the Curved Surface Area of a Hemisphere?
Curved surface area of a hemisphere is defined as the area covered by the curved surface. In other words, the area of the outer surface of the hemisphere. The curved surface area of the hemisphere is expressed in square units, using units like m2, cm2, ft2, yd2, etc.
Curved Surface Area of a Hemisphere Formula
The curved surface area of a hemisphere is the area of its curved surface. For a hemisphere, if its radius is given, then its curved surface area can be given by:
Curved surface area of a hemisphere = 1/2 (Curved surface area of a sphere) = 1/2 (4 π r2) = 2 π r2, where r is the radius of the hemisphere
How To Find the Curved Surface Area of a Hemisphere?
As we learned in the previous section, the curved surface area of a hemisphere is 2πr2. Thus, we follow the steps shown below to find the curved surface area of a hemisphere.
- Step 1: Identify the radius of the hemisphere and name it to be 'r'.
- Step 2: Find the curved surface area of a hemisphere using the formula = 2πr2.
- Step 3: Represent the final answer in square units.
Example: Find the curved surface area of a hemisphere having radius = 7 units. (Use π = 22/7)
Solution:
Radius of the hemisphere = 7 units
Curved surface area of a hemisphere = 2πr2 = 2 (22/7 72 = 2 × 22 × 7 = 308 units2
Therefore, the curved surface area of the hemisphere = 308 units2
Now that we've understood the formula and method to calculate the curved surface area of hemisphere, let us have a look at a few solved examples for better understanding.
Related Topics
Listed below are a few topics related to the curved surface area of hemisphere, take a look.
Curved Surface Area of Hemisphere Examples
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Example 1: Find the curved surface area of a hemisphere with radius = 21 units. (Use π = 22/7)
Solution:
Radius of the hemisphere = 21 units
Curved surface area of a hemisphere = 2 π r2 = 2 (22/7) 212 = 2 × 22 × 21 × 3 = 2772 units2
Therefore, the curved surface area of the hemisphere = 2772 units2
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Example 2: Find the radius of the hemisphere given its curved surface area = 308 units2. (Use π = 22/7)
Solution:
Curved surface area of a hemisphere = 308 units2
2 π r2 = 308
r2 = 308/(2π) = 49
r = 7 units
Therefore, the radius of the hemisphere = 7 units
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Example 3: State true or false.
a.) Hemisphere is a 3D figure obtained by cutting a sphere in half.
b.) There is 1 edge and 1 vertex in a hemisphere.
Solution:
a.) True, the hemisphere is a 3D figure obtained by cutting a sphere in half.
b.) False, there are no edges and no vertices in a hemisphere.
FAQs on the Curved Surface Area of a Hemisphere
What is Meant by the Curved Surface Area of Hemisphere?
The curved surface area of a hemisphere is defined as the area covered by the curved surface of a hemisphere. A hemisphere is a 3-D shape that is obtained when a sphere is cut along a plane passing through the center of the sphere. In other words, a hemisphere is half of a sphere.
What is the Formula Curved Surface Area of a Hemisphere?
The curved surface area of a hemisphere can be calculated using the given radius. For a hemisphere, if its radius (r) is given, then its total surface area can be given by, Curved Surface Area = 2 π r2
How Do You Find the Curved Surface Area of a Hemisphere?
The curved surface area of a hemisphere can be calculated using the following steps,
- Note down the radius of the hemisphere, 'r'.
- Apply the formula to calculate the curved surface area, CSA of hemisphere = 2 π r2
- Express the answer in square units.
What are the Units Used to Express the Curved Surface Area of a Hemisphere?
In measurements, we express the curved surface area of the hemisphere in square units. Some common units are square meters, square inches, square centimeters, etc.
What is the Curved Surface Area of a Hollow Hemisphere?
The curved surface area of a hollow hemisphere can be calculated using the formula, CSA of hollow sphere = 2π r\(_2\)2 + 2πr\(_1\)2, where, r\(_1\) is the radius of the internal hemisphere, and r\(_2\) is the radius of the external hemisphere.
What is the Difference Between Total Surface Area of and Curved Surface Area of Hemisphere?
Curved surface area of hemisphere is the area covered by the curved surface of a hemisphere, whereas total surface area is space covered by the curved surface and the base surface of the hemisphere in 2-D plane.
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