Question

Find the TSA of a cone if its slant height is 21 cm and diameter of the base is 24 cm.


I want answer but slowly slowly step by step.​

Answer 1

GIVEN:

• Slant height (l) of the cone = 21 cm
• Diameter of the base = 24 cm

TO FIND:

• What is the TSA of the cone ?

SOLUTION:

We have given that, the Diameter of the cone is 24 cm

$\sf{\star Radius = \dfrac{Diameter}{2} = \cancel\dfrac{24}{2}}$

$\bf{\star Radius = 12 \: cm}$

We know that the formula for finding the TSA of cone is:-

$\large{\boxed{\bf{\star \: T.S.A. = \pi r (l + r) \: \star}}}$

According to question:-

Take π = 22/7

$\sf{\longrightarrow T.S.A = \dfrac{22}{7} \times 12(21+12)}$

$\sf{\longrightarrow T.S.A = \dfrac{22}{7} \times 12 \times 33}$

$\sf{\longrightarrow T.S.A = \dfrac{8712}{7}}$

$\sf{\longrightarrow T.S.A = 1244.57 \: cm^2 }$

• TSA = 1244.57 cm²

❝ Hence, the TSA of the cone is 1244.57 cm² ❞

Answer 2

Answer:

GIVEN:

Slant height (l) of the cone = 21 cm

Diameter of the base = 24 cm

TO FIND:

What is the TSA of the cone ?

SOLUTION:

We have given that, the Diameter of the cone is 24 cm

$\sf{\star Radius = \dfrac{Diameter}{2} = \cancel\dfrac{24}{2}}$⋆Radius=

2

Diameter

=

2

24

$\bf{\star Radius = 12 \: cm}⋆$Radius=12cm

We know that the formula for finding the TSA of cone is:-

$\large{\boxed{\bf{\star \: T.S.A. = \pi r (l + r) \: \star}}}$

$⋆T.S.A.[tex]=πr(l+r)⋆</p><p> </p><p> </p><p></p><p>According to question:-</p><p></p><p>Take π = 22/7</p><p></p><p>[tex]\sf{\longrightarrow T.S.A = \dfrac{22}{7} \times 12(21+12)}$$⟶T.S.A= </p><p>7</p><p>22$

×12(21+12)

$\sf{\longrightarrow T.S.A = \dfrac{22}{7} \times 12 \times 33}[\tex][tex]⟶T.S.A$=

7

22

×12×33

$\sf{\longrightarrow T.S.A = \dfrac{8712}{7}}$

$⟶T.S.A$=

7

8712

$\sf{\longrightarrow T.S.A = 1244.57 \: cm^2}$

$⟶T.S.A$=1244.57cm²

TSA = 1244.57 cm²

❝ Hence, the TSA of the cone is 1244.57 cm² ❞