Question

Find the surface area of a conical grain storage tank that has a height of 30 meters and a diameter of 14 meters. Round the answer to the nearest square meter.

Answer 1

Total Surface Area of a cone = πr² + πrh 

Radius = Diameter ÷ 2 = 14 ÷ 2 = 7

Find Slanted Height:

a² + b² = c²
7² + 30² = c²
c² = 947
c= √947
c = 30.77

Slanted Height = 30.77m

Total Surface Area  = πr(7)² + π(7)(30.77)
Total Surface Area  = 831 m² (nearest m²)


Answer: 831 m²

Answer 2

Surface area of a cone: $\pi r^{2} + \pi rl$

Plug in the numbers into the formula.
Find the slant height, l, by using the Pythagorean Theorem: 7² + 30² = l²

$\pi 7^2 + \pi 7(30.8) = 831.3$
Round it to the nearest square meter... 831.

The surface area of the conical grain storage tank is 831 meters².