The surface area of a hemisphere is an essential concept in geometry, especially when dealing with three-dimensional shapes. A hemisphere is a half of a sphere, created when a sphere is divided by a plane passing through its center.
It consists of two parts: the curved surface, which is the outer, rounded part, and the flat circular base. Calculating the surface area of a hemisphere involves determining both these components. The surface area is important in various real-world applications, such as determining the material required to cover a hemispherical object, designing domes, or calculating the outer area of objects in engineering and architecture. This article will explore the formula for calculating the surface area of a hemisphere and provide practical examples for better understanding. [video width="1920" height="1080" mp4="https://www.pw.live/exams/wp-content/uploads/2024/12/Copy-of-Corurious-Jr-Reel-2-Landscape-1-2-1.mp4"][/video]Also Check: AM and PM
Step 1: Understand the Formula for Surface Area:
The total surface area of a hemisphere consists of two parts:Step 2: Find the Radius (r):
Identify or measure the radius (r) of the hemisphere. The radius is the distance from the center of the hemisphere to any point on its curved surface. If you're given the diameter (the distance across the flat circular surface), divide it by 2 to find the radius: 𝑟=Diameter2r= Step 3: Square the Radius (r) Once you have the radius, the next step is to square it (multiply the radius by itself): 𝑟2=𝑟×𝑟Step 4: Multiply by Pi (𝜋:Multiply the squared radius by pi (𝜋):𝜋𝑟2
This gives the area of the flat circular base of the hemisphere.Step 5: Multiply by 3:
To find the total surface area of the hemisphere, multiply the result from step 4 by 3. This accounts for both the curved surface area and the circular base area. Surface Area =3πr2 Step 6: Calculate the Final Value: Now, you can calculate the final surface area. Use 𝜋≈3.14159 to get the numerical result. Example Problem : Let’s go through a sample calculation to understand the process better. Given : Radius 𝑟=5cm Step 1 : Square the Radius:𝑟2=5×5=25 Step 2 : Multiply by Pi:𝜋𝑟2=3.14159×25≈78.53975 Step 3 : Multiply by 3: Surface Area=3×78.53975≈235.62cm2 Final Answer : The surface area of the hemisphere is approximately 235.62 cm². [video width="1920" height="1080" mp4="https://www.pw.live/exams/wp-content/uploads/2024/12/Curious-Jr-Ad.mp4"][/video] Curved Surface Area of a Hemisphere Formula The formula for the curved surface area of a hemisphere is: Curved Surface Area=2πr Where : 𝑟 is the radius of the hemisphere. 𝜋(pi) is a constant approximately equal to 3.14159. Explanation : The curved surface area refers to the outer surface of the hemisphere, excluding the flat circular base. To find the curved surface area, you simply multiply 2 times pi times the square of the radius.Also Check: Area of Rectangle
Surface Area of Hollow Hemisphere =2πR
Where :Surface Area of Hollow Hemisphere=3πR 2+3πr
Explanation:Surface Area of Hollow Hemisphere=3π(6)2+3π(4) 2=3π(36)+3π(16)=108π+48π=156πcm 2
Approximating: Surface Area of Hollow Hemisphere≈156×3.14159≈489.74cm2. Thus, the surface area of the hollow hemisphere is approximately 489.74 cm².Related Articles | |
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