The surface area of the right cone is 141 sq. units. The correct option is B. 141 sq. units
Calculating surface area of a cone
From the question, we are to determine the surface area of the given right cone
The total surface area of a cone can be calculated by using the formula,
TSA = πrl + πr²
Where TSA is the total surface area
r is the radius
and l is the slant height
From the given information,
r = 3
l = 12
Putting the parameters into the formula, we get
TSA = (π×3×12) + (π ×3²)
TSA = 36π + 9π
TSA = 45π sq. units
TSA = 141.37 sq. units
TSA ≅ 141 sq. units
Hence, the surface area of the right cone is 141 sq. units. The correct option is B. 141 sq. units
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