Grade IX: Surface Area and Volume

If the radius of a sphere is 2r, then its volume will be _____

• 4⁄3 πr²
• 4πr³
• 8⁄3 πr³
• 32⁄3 πr³

Say 'TRUE' or 'FALSE'
'In a right circular cone, height, radius and slant height are always the sides of a right triangle'

• TRUE
• FALSE

The radius of the base and the height of a right circular cone is 8 cm and 15 cm respectively. Find the volume and total surface area of the cone. (Take 𝜋 = 22/7)

• Volume = 1120 cm³ Surface area = 750.67 cm²

• Volume = 1005.71 cm³ Surface area = 628.57 cm²

• Volume = 1678.90 cm³ Surface area = 879. 90 cm²

• Volume = 2345.70 cm³ Surface area = 779. 90 cm²

If the curved surface area and slant height of cone is 924 cm³ and 21cm respectively. Which of the following statement is true?

• Radius of the cone is 10 cm

• Total surface area of cone is 1540 cm³

• Total surface area of cone is 2343 cm³

• None of these

What is the formula for Volume of a Cone?

• V=π r³h

• V=π r²h

• V=1/3 π r²h

• V=4/3 π r³