Question : The slant height of a cone is 20 cm. If the area of its base is 616 cm², then what is the curved surface area of this cone? (use $\pi=\frac{22}{7}$)

Option 1: 960 cm²

Option 2: 400 cm²

Option 3: 1760 cm²

Option 4: 880 cm²

Question : The whole surface area of a pyramid whose base is a regular polygon is 340 cm², the area of its base is 100 cm², and the area of each lateral face is 30 cm². Then the number of lateral faces is:

Option 1: 8

Option 2: 9

Option 3: 7

Option 4: 10

Question : The curved surface area of a solid hemisphere is 22 cm². What is the total surface area of the hemisphere? (use $\pi=\frac{22}{7}$)

Option 1: 66 cm²

Option 2: 44 cm²

Option 3: 33 cm²

Option 4: 30 cm²

Question : If the surface area of a sphere is 346.5 cm², then its radius is: (Take $\pi=\frac{22}{7}$)

Option 1: 7 cm

Option 2: 3.25 cm

Option 3: 5.25 cm

Option 4: 9 cm

Question : An arc of length 23.1 cm subtends an 18° angle at the centre. What is the area of the circle?
$\mathrm{[Use ~\pi=\frac{22}{7} ]}$

Option 1: 16978.50 cm²

Option 2: 16988.50 cm²

Option 3: 16878.50 cm²

Option 4: 16798.50 cm²