Question

Find the slant height and radius of the cone made from a quadrant of a circle of radius 9.6cm

Answer 1

radius of a quadrant= 9.6 cm
radius of cone = r

slant height of cone= l
radius of the given quadrant of circle = 9.6cm                           
circumference of cone = length of an arc of the quadrant
2πr =(2π x 9.6) / 4
2 x 22/7 x r= 2 x 22/7 x 9.6/ 4
r = 9.6/4
r = 2.4 cm 

Answer 2

Let the radius and slant height of the cone be r cm and l cm respectively.
Radius of quadrant of the circle = Slant height of the cone.
∴ Slant height of the cone, l = 9.6 cm
Circumference of base of the cone = length of the arc AB

⇒ 2πr = 90⁰ ÷ 360⁰ × 2π (9.6)     [Length of the arc = (Theta) ÷360 × 2πR]


⇒ r = 1 ÷ 4 × 9.6 cm

⇒ r = 2.4 cm

Thus, Slant height and Radius of the cone are 9.6 cm and 2.4 cm respectively.