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Last updated on August 30, 2025
A hemispherical dome is a 3-dimensional shape that has a circular base and a curved half-sphere top. The surface area of the hemispherical dome is the total area covered by its outer surface. The surface area of the dome includes both its curved surface and its base. In this article, we will learn about the surface area of a hemispherical dome.
The surface area of a hemispherical dome is the total area occupied by the boundary or surface of the dome.
It is measured in square units. A hemispherical dome is a 3D shape that resembles half of a sphere with a circular base.
It has a curved top and a flat base, so it has two surface areas: the curved surface area and the total surface area.
A hemispherical dome has a curved surface, and it has two types of surface areas: the curved surface area and the total surface area.
Look at the hemispherical dome below to see its surface area and radius(r).
A hemispherical dome has two types of surface areas: Curved Surface Area of a Hemispherical Dome Total Surface Area of a Hemispherical Dome
The area of the curved part of the dome, excluding its base, is known as the curved surface area of a hemispherical dome.
The formula for the curved surface area (CSA) of the dome is given as: Curved Surface Area = 2πr² square units
Here, r is the radius of the base of the dome.
The total area occupied by the dome, including the area of the curved surface and the area of the circular base, is known as the total surface area of the hemispherical dome.
The total surface area of the dome is calculated by using the formula: Total Surface Area = 3πr² square units Where r is the radius of the base of the dome.
Derivation of the Total Surface Area of a Hemispherical Dome To find the total surface area of a hemispherical dome, consider the curved surface area and the base area.
Total Surface Area of a Hemispherical Dome = Base Area of a Hemispherical Dome + Curved Surface Area of a Hemispherical Dome
Here, the base area of a hemispherical dome = πr²
Curved surface area of a hemispherical dome = 2πr²
Substituting the formulas into the total surface area,
Total surface area of a hemispherical dome, T = πr² + 2πr²
Therefore, the total surface area of the hemispherical dome T = 3πr²
The volume of a hemispherical dome shows how much space is inside it. It tells us how much space is inside the dome or how much it can hold.
The volume of a hemispherical dome can be found by using the formula: Volume = ⅔ (πr³) (cubic units)
Students assume that the curved surface area (CSA) and the total surface area (TSA) of a hemispherical dome are the same.
This confusion arises because both involve the radius.
Always remember that CSA is used for only the curved part of the dome, and TSA includes the curved surface and the base.
Given r = 7 cm. Use the formula: CSA = 2πr² = 2 × (22/7) × 7 × 7 = 2 × 22 × 7 = 308 cm²
Find the total surface area of a hemispherical dome with a radius of 5 cm.
TSA = 235.5 cm²
Use the formula: TSA = 3πr² = 3 × 3.14 × 5 × 5 = 3 × 3.14 × 25 = 235.5 cm²
A hemispherical dome has a radius of 6 cm. Find the total surface area.
TSA = 339.12 cm²
Use the TSA formula: TSA = 3πr² = 3 × 3.14 × 6 × 6 = 3 × 3.14 × 36 = 339.12 cm²
Find the curved surface area of a hemispherical dome with a radius of 3.5 cm.
CSA = 77 cm²
CSA = 2πr² = 2 × (22/7) × 3.5 × 3.5 = 22 × 1 × 3.5 = 77 cm²
The total surface area of a hemispherical dome is 462 cm². Find the radius.
Radius = 7 cm
Students often make mistakes while calculating the surface area of a hemispherical dome, which leads to wrong answers. Below are some common mistakes and the ways to avoid them.
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