Question

The curved surface area of a cone is 4070cm square and its diameter is 70cm what is its slant hight

Answer 1

Given :

→ Curved surface area of cone = 4070 cm²

→ Diameter of cone = 70 cm

To find :

→ Slant height of the cone

Solution :

To calculate the slant height, we need the radius of the cone. So, firstly we will calculate it.

→ Radius of the cone = Diameter ÷ 2

→ Substituting the given values :-

→ Radius of the cone = 70 ÷ 2

→ Radius of the cone = 35

Therefore, radius of the cone = 35 cm

Slant height of the cone :-

→ Curved surface area of cone = πrl

→ Substituting the given values :-

→ 4070 = 22/7 × 35 × l

→ 4070 × 7/22 × 1/35 = l

→ 37 = l

Therefore, Slant height of the cone = 37 cm

Answer 2

Answer :

• The slant height of cone= 37cm

Given :

• The curved surface area of cone is 4070cm²
• Diameter is 70cm

To find :

• Slant height of cone

Solution :

First we need to find the radius of cone :

We know that, Radius formula :

• Radius = Diameter/2

Where , Diameter is 70cm

》Radius = Diameter/2

》Radius = 70/2

》Radius = 35cm

Radius is 35cm.

Now , we have to use the formula of curved surface area of a cone then we get slant height of a cone.

Curved surface area of cone is 4070cm²

As we know that,

• Curved surface area of a cone = πrl

Where, r is radius and l is slant height

》Curved surface area of a cone = 4070

》πrl = 4070

》22/7 × 35 × l = 4070

》l = 4070 × 7 / 22 × 35

》l = 4070 × 7 / 22 × 35

》l = 28490/770

》l = 37cm

Hence , The slant height of cone = 37cm