A cone has a base radius of 3 m and a height of 4 m. What is the surface area of

Practice Questions

Q1
A cone has a base radius of 3 m and a height of 4 m. What is the surface area of the cone?
  1. 15π
  2. 18π
  3. 21π
  4. 24π

Questions & Step-by-Step Solutions

A cone has a base radius of 3 m and a height of 4 m. What is the surface area of the cone?
  • Step 1: Identify the formula for the surface area of a cone, which is SA = πr(r + l).
  • Step 2: Find the radius (r) of the cone, which is given as 3 m.
  • Step 3: Find the height (h) of the cone, which is given as 4 m.
  • Step 4: Calculate the slant height (l) using the formula l = √(r² + h²).
  • Step 5: Substitute the values into the formula for slant height: l = √(3² + 4²) = √(9 + 16) = √25 = 5 m.
  • Step 6: Substitute the values of r and l into the surface area formula: SA = π(3)(3 + 5).
  • Step 7: Simplify the expression: SA = π(3)(8) = 24π.
  • Step 8: The surface area of the cone is 24π square meters.
  • Surface Area of a Cone – The formula for the surface area of a cone involves the base radius and the slant height, which is derived from the Pythagorean theorem.
  • Slant Height Calculation – Understanding how to calculate the slant height using the radius and height of the cone.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely