Question

Diameter of the base of a cone is 10.5cm and its slant height is 10cm.Find its curved surface area​

Answer 1

Answer:

d=10.5

l=10

$\pi = \frac{22}{7}$

therefore,

csa of cone=

$\frac{22}{7} \times 10.5 \times 10$

$22 \times 1.5 \times 10$

curved surface area= 330sq.cm

Answer 2

Given :-

• Diameter = 10.5 cm

• Radius = d/2 = 10.5/2 = 5.25 cm

• Slant height = 10 cm

To find :-

• Curved surface area of cone

Solution :-

we know that,

$\orange{\bigstar}\:\:{\underline{\boxed{\bf\green{CSA\:of\:cone=\pi{r}l}}}}$

$\rm\longrightarrow\:CSA\:of\:cone=\dfrac{22}{7}\times\:5.25\times\:10$

$\rm\longrightarrow\:CSA\:of\:cone=22\times\:0.75\times\:10$

$\rm\longrightarrow\:CSA\:of\:cone=165\:c{m}^{2}$

Hence,the curved surface area of cone will be 165 cm².

$\blue{\bigstar}\:\:{\underline{\boxed{\bf\red{More\:Information}}}}$

✝ Related to right circular cone :-

• CSA of right circular cone =πrl

• Volume of right circular cone = ⅓ πr²h

• whole surface area of solid cone = πrl + πr² = πr(l + r)

• slant height (l) = √ r² + h²

• Volume of cone with hemispherical top or bottom (V) = ⅓ πr² (H + r)