Question

PLEASE HELP !!!!! Find the surface area of a cone with radius of 7.9 cm and slant height of 3.7 cm, to the nearest square unit. Use 3.14 for π.

A)380cm ^2 B)242cm^2 C)484 cm^2 D)288 cm^2

Answer 1

For this case what you need to know is that the formula for the total surface area of a straight cone is
S.A = πrl + π r ^ 2
Substituting the values we have:
S.A = (3.14) * (7.9) * (3.7) + (3.14) * (7.9) ^ 2
S.A = 287.7496 cm ^ 2
Answer:
the surface area of a cone is
D) 288 cm ^ 2