Question 1

What is surface area?

Accepted Answer

Surface area is the total area of all the faces (or curved surfaces) of a 3D object. It is measured in square units (cm², m², in², etc.). Think of it as the amount of wrapping paper needed to cover the shape without overlap.

Question 2

What is the formula for the surface area of a sphere?

Accepted Answer

TSA = 4πr² where r is the radius. For example, a sphere with radius 5 cm has TSA = 4 × π × 25 ≈ 314.16 cm².

Question 3

What is the lateral surface area of a cylinder?

Accepted Answer

The lateral (curved) surface area of a cylinder = 2πrh, where r is the radius and h is the height. The total surface area includes two circular bases: TSA = 2πr² + 2πrh.

Question 4

How do I find the slant height of a cone?

Accepted Answer

Slant height l = √(r² + h²) where r is the base radius and h is the height. This comes from the Pythagorean theorem applied to the cone's cross-section.

Question 5

What is the difference between total and lateral surface area?

Accepted Answer

Total surface area (TSA) includes all surfaces — bases and curved/lateral sides. Lateral surface area (LSA) excludes the base(s), counting only the side surfaces. For example, a cylinder's LSA = 2πrh (just the curved side), while TSA = 2πr² + 2πrh (including both circular ends).

Surface Area Calculator

⚽ Sphere

Results

Frequently Asked Questions

What is surface area?

What is the formula for the surface area of a sphere?

What is the lateral surface area of a cylinder?

How do I find the slant height of a cone?

What is the difference between total and lateral surface area?

Related Tools

Pythagorean Theorem Calculator

Square Root Calculator