Question

1) A cone is made by rolling up a sector of central angle 900

and radius 12 cm.

a) Find the slant height of the cone

b) Find the radius of the cone?​

Answer 1

Step-by-step explanation:

Side of the square = 5 cm

Base of the isosceles triangle = 5 cm

Height of the isosceles triangle = 8 cm

Area of the square = (side)2 = (5 cm)2 = 25 cm2

Area of one isosceles triangle = 



Area of four isosceles triangles = 20 × 4 cm2 = 80 cm2

Area of the square pyramid = Area of the square + Area of four isosceles triangles

= (25 + 80) cm2 

= 105 cm2

Thus, we need 105 cm2 paper for the job.