The surface area of a right cone is 400.2 m2. The radius of the cone is 6.0 m. Determine the height of the cone to the nearest metre.

S = πr (r + √ (h² + r²))

400.2 = 3.14 (6) (6 + √ (h² + 6²))

400.2 = 18.84 (6 + √ (h² + 36))

18.84 18.84

21¹⁰⁹/₄₇₁ = 6 + √ (h² + 36))

- 6 - 6

15¹⁰⁹/₄₇₁ = √ (h² + 36)

231²²¹⁰⁰⁵/₂₂₁₈₄₁ = h² + 36

- 36 - 36

195²²¹⁰⁰⁵/₂₂₁₈₄₁ = h²

14 ≈ h