Secondary School (English Medium) (5 to 8) कक्षा ७ - CBSE Question Bank Solutions for Mathematics

Ratio of circumference of a circle to its radius is always 2π : 1.

A circle with radius 16 cm is cut into four equal parts and rearranged to form another shape as shown in the following figure:

Does the perimeter change? If it does change, by how much does it increase or decrease?

Ishika has designed a small oval race track for her remote control car. Her design is shown in the figure. What is the total distance around the track? Round your answer to the nearest whole cm.

Find the total cost of wooden fencing around a circular garden of diameter 28 m, if 1 m of fencing costs ₹ 300.

A circular pond is surrounded by a 2 m wide circular path. If outer circumference of circular path is 44 m, find the inner circumference of the circular path. Also find area of the path.

ABCD is a given rectangle with length as 80 cm and breadth as 60 cm. P, Q, R, S are the midpoints of sides AB, BC, CD, DA respectively. A circular rangoli of radius 10 cm is drawn at the centre as shown in the following figure. Find the area of shaded portion.

A dinner plate is in the form of circle. A circular region encloses a beautiful design as shown in the following figure. The inner circumference is 352 mm and outer is 396 mm. Find the width of circular design.

The moon is about 384000 km from earth and its path around the earth is nearly circular. Find the length of path described by moon in one complete revolution. (Take π = 3.14)

A photograph of Billiard/Snooker table has dimensions as `1/10`th of its actual size as shown in the following figure:

The portion excluding six holes each of diameter 0.5 cm needs to be polished at rate of ₹ 200 per m². Find the cost of polishing.

Find the area of the following circle, given that radius = 14 mm (take `pi = 22/7`).

Find the area of the following circle, given that diameter = 49 m.

Find the area of the following circles, given that radius = 5 cm.

Find the perimeter of the adjoining figure, which is a semicircle including its diameter.

Find the cost of polishing a circular table-top of diameter 1.6 m, if the rate of polishing is ₹ 15/m². (Take π = 3.14)

From a circular card sheet of radius 14 cm, two circles of radius 3.5 cm and a rectangle of length 3 cm and breadth 1 cm are removed. (as shown in the following figure). Find the area of the remaining sheet. (Take `pi = 22/7`)

A circle of radius 2 cm is cut out from a square piece of an aluminium sheet of side 6 cm. What is the area of the left over aluminium sheet? (Take π = 3.14)

The circumference of a circle is 31.4 cm. Find the radius and the area of the circle? (Take π = 3.14)  

A circular flower bed is surrounded by a path 4 m wide. The diameter of the flower bed is 66 m. What is the area of this path? (π = 3.14)

A circular flower garden has an area of 314 m². A sprinkler at the centre of the garden can cover an area that has a radius of 12 m. Will the sprinkler water the entire garden? (Take π = 3.14)

PQR is a triangle right angled at P. If PQ = 10 cm and PR = 24 cm, find QR.