CBSE Class 10-Mathematics: Chapter – 12 Areas Related to Circles Part 15 (For CBSE, ICSE, IAS, NET, NRA 2022)
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Question 46:
The radii of two circles are 19 cm and 9 cm, respectively. Find the radius of the circle which has its circumference equal to the sum of the circumference of the two circles
Answer:
circumference of the 1st circle
circumference of the 2nd circle
Question 47:
A car travels distance in which each wheel makes complete revolutions. Find the radius of its wheel
Answer:
Distance travelled by a wheel in complete revolutions
Distance travelled in one revolution
Let r be the radius of the wheel
Question 48:
A sector is cut from a circle of diameter . If the angle of the sector is 1500 find its area.
Answer:
We have,
Diameter
Angle of sector
Area of the sector
Question 49:
In the given figure AOBCA represent a quadrant of area . Calculate the area of the shaded portion.
Answer:
Required area = Area of quadrant OAB – Area of
3 Mark Questions
Question 1:
The cost of fencing a circular field at the rate of per meter is . The field is to be ploughed at the rate of . Find the cost of ploughing the field.
Answer:
Since for ₹ , the length of fencing 1 meter
for ₹ , the length of fencing
Perimeter i.e.. , circumference of the field
Let r be radius of the field.
Area of the field
Total cost of ploughing the field