Question

Please help me answer all parts of question 3 in the photo.

Answer 1

(i.) CA = πrl
CA = π (5*13)
CA = 65π

(ii.) TA = πrl + πr^2
TA = 65π + π (5^2)
TA = 65π + 25π
TA = 90π

(iii.) To get the height of the cone, you have to use the Pythagorean theorem. Plug in the radius for a and the slant height for c.

a^2 + b^2 = c^2
5^2 + b^2 = 13^2
25 + b^2 = 169 Height = 12
b^2 = 144
b = 12

(iv.) v = (1/3)πr^2h
v = (1/3)π(5^2)*12
v = (1/3)π(25*12)
v = (1/3)π*300
v = 100π