Circle Class 7 Practice Set 42 Answers Solutions Chapter 11
Question 1
Maharashtra Board Solution
Complete the table below:
Sr. No | Radius (r) | Diameter (d) | Circumference (c) |
i. | 7 cm | ||
ii. | 28 cm | ||
iii. | 616 cm | ||
iv. | 72.6 cm |
Solution & Step-by-Step Answer:
i. Radius (r) = 7 cm
Diameter (d) = 2r
= 2 x 7 = 14 cm
Circumference (c) = πd
= x 14
= 44 cm
ii. Diameter (d) = 28 cm
Radius (r) = = 14 cm
Circumference (c) = πd
= x 28
= 88 cm
iii. Circumference (c) = 616 cm
∴ πd = 616
∴ x d = 616
∴ d = 616 x
∴ d = 196 cm
∴ Diameter (d) = 196 cm
Radius (r) = = 98 cm
iv. Circumference (c) = 72.6 cm
∴ πd = 72.6
x d = 72.6
∴
∴ d = 23.1 cm
∴ Diameter (d) = 23.1 cm
Radius (r) =
= 11.55 cm
Sr. No | Radius (r) | Diameter (d) | Circumference (c) | |||||||
i. | 7 cm | 14 cm | 44 cm | |||||||
ii. | 14 cm | 28 cm | 88 cm | |||||||
iii. | 98 cm | 196 cm | 616 cm | |||||||
iv. | 11.55 cm | 23.1 cm | 72.6 cm
Question 2
Maharashtra Board Solution
If the circumference of a circle is 176 cm, find its radius.
Solution & Step-by-Step Answer:
Circumference (c) = 176 cm ∴ 2πr = 176 ∴ 2 x x r = 176 ∴ x r = 176 ∴ r = 176 x = 28 cm ∴ The radius of the circle is 28 cm.
Question 3
Maharashtra Board Solution
The radius of a circular garden is 56 m. What would it cost to put a 4-round fence around this garden at a rate of 40 rupees per metre?
Solution & Step-by-Step Answer:
Radius of the circular garden (r) = 56 m ∴ Circumference of the circular garden (c) = 2πr = 2 x x 56 = 352 m ∴ Length of the wire required to put 1-round fence = Circumference ∴ Length of wire required to put a 4-round fence = 4 x Circumference = 4 x 352 = 1408 m ∴ Cost of wire per meter = Rs 40 ∴ Total cost = length of wire required x cost of the wire = 1408 x 40 = Rs 56320 ∴ The cost to put a 4-round fence around the garden is Rs 56320.
Question 4
Maharashtra Board Solution
The wheel of a bullock cart has a diameter of 1.4 m. How many rotations will the wheel complete as the cart travels 1.1 km?
Solution & Step-by-Step Answer:
Diameter of the wheel of the bullock cart (d) = 1.4 m Circumference of the wheel of the bullock cart (c) = πd Distance covered in 1 rotation = Circumference of the wheel = 4.4 m ∴ The wheel of the bullock cart will complete 250 rotations as the cart travels 1.1 km.
Maharashtra Board Class 7 Maths Chapter 11 Circle Practice Set 42 Intext Questions and Activities
Solution & Step-by-Step Answer:
i. OA, OB, OC, OF
ii. EC, AD, AB, FC iii. AB, FC |