Question

A solid shape is made by joining two cones. Each cone has the same radius. One cone has The other cone has slant height = 2x radius The total surface area of the shape is slant height = 3x radius 57.8 pi cm^ 2 Curved surface area of acone = pi*r * l where r is the radius and I is the slant height Work out the radius. Each cone has the same radius.

Answer 1

The given area of the shape of 57.8·π cm², and length of the slant sides

being a factor of the radius, gives the length of the radius as 3.4 cm.

How can the length of the radius be calculated?

Given;

Radius of the two cones are equal.

Slant height of one cone = 2 × Radius

Slant height of the other cone = 3 × Radius

Surface area of the shape = 57.8·π cm²

The curved surface area of a cone = π·r·l

Required:

The radius of the cone.

Solution;

Surface areas of the cones are therefore;

π·r × 2·r, and π·r × 3·r

The total surface area is therefore;

π·r × 2·r + π·r × 3·r = 57.8·π

5·r²·π = 57.8·π

Which gives;

r² = 57.8 ÷ 5 = 11.56

r = √(11.56) = 3.4

• The radius of the cones, r = 3.4 cm

Learn more about finding the surface area of 3-D shapes here:

brainly.com/question/15635229