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