Circles Review – Fundamentals of Circles, Formulas for Circle, Congruent Circles, Tangent to a circle, Polygon inscribed in a Circle , Circle inscribed in a circle, Concentric Circles
Class Questions – Exercise 1 Exercise 2 Exercise 3 Exercise 4 Exercise 5
Practice Questions – Solutions
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Q.1 If the radius of a circular garden is 6. Lisa walk with her niece making 6 rounds everyday around the garden, total how much distance she covers?
A. 6π
B. 52π
C. 72π
D. 15π
E. 4π
Solution :
Circumference of a circle = 2πr
= 2 x π x 6
= 12 π
She makes 6 rounds, so 6 x 12 π = 72 π
The correct answer is C.
Q.2 In the following figure a circle is inscribed in a square having the length of 12, what is the area of shaded region?
A. 144π
B. 12(6-5π)
C. 14(5π-5)
D. 12(12-3π)
E. 14(14-4π)
Solution:
Length of the square will be equal to diameter of circle, so Diameter = 12
Area of circle = π d² ⁄ 4 = π x 12 x 12 ⁄ 4
= 36 π
Area of square = length x length
= 12 x 12 = 144
So area of shaded region is = area of square – area of circle
= 144 – 36 π
= 12(12-3π)
So correct answer is choice ‘D’
