Question

A circular sheet with radius $$36cm$$ is divide into four equal sectors and one of them bent into a cone.
a. What is the slant height of the cone?
b. What is the radius of the cone?
c. What is the curved surface area?

Answer 1

Radius of the circular sheet $$36$$cm
a. Slant height of the cone $$=36cm$$
b.Radius of the cone $$r=\dfrac{r}{1}=\dfrac{x}{36}$$(formula) centre angel (x) $$=360/4=90^o$$
$$i.e.,\dfrac{r}{36}=\dfrac{90}{360}$$
$$r=\dfrac{36\times 90}{360}=9cm$$
Hence,the radius of the cone $$=9cm$$
c.Curved surface are (CSA)$$=\pi rl$$
$$\pi \times 9\times 36 =324 \pi cm^2$$
$$324\times 3.14=1017.36 cm^2$$