Question

Hey guys I need help with this maths problem thank you.

Answer 1

Answer:

Step-by-step explanation:

(a) radius is the bottom leg of the right triangle formed by the slopped edge and the vertical line from the tip to the center of the base.  So that's easy enough with the pythagorean theorem.

15^2 + b^2 = 34^2

b = sqrt(1156 - 225)

b = 30.512

(b) The surface area can be looked at as the surface area of the circular base + the surface area of the actual cone.

area of a circle is pi*r^2 and the surface area of the cone, excluding the base,  is pi*r*s, where s is the slant height.  If you want to know where that one comes from  it kinda takes some calculus to understand but I can link a video to explain it.

pi*r^2 + pi*r*s

pi(r^2+rs) I factored out pi to make things a little easier.

pi(931+30.512*34)

1968.408pi  Feel free to multiply out pi.

(c) Volume for a cone (or any kind of pyramid) is area of the base times the height all divided by 3.

so since we know the area of the base we can just plug in.

(pi*r^2*h)/3

(pi*931*15)/3

4655pi