Test: Areas Related to Circles - 1 - Class 10 MCQ

 Given area of circle=154
      ⇒area of circle=πr²
                             =22/7 ×7×7.
                             =154 
so radius of the circle=7cm
 perimeter of circle=2πr
                           =2 ×22/7×7
                           =44cm
⇒perimeter of the circle=44 cm.

Side of a square circumscribing a circle of radius a cm = diameter of circle = 2a cm
∴ Perimeter of the square = 4 x 2a = 8a cm

 πr² - 2πr x 2 ⇒ r = 4 ⇒ 2r = 8 units

Radius of the wheel = 1.26/2 = 0.63 m
Distance travelled in one revolution

∴ Distance travelled in 500 revolutions
= 500 x 3.96 = 1980 m

Diameter of first circle = d₁ = 36 cm
Diameter of second circle = d₂ = 20 cm
∴ Circumference of first circle = πd₁ = 36π cm
Circumference of second circle = πd₂ = 20π cm
Now, we are given that,
Circumference of circle = Circumference of first circle + Circumference of second circle
πD = πd₁ + πd₂
⇒ πD = 36π + 20π
⇒ πD = 56π ⇒ D = 56
⇒ Radius = 56/2 = 28 cm

2π R₁ + 2πR₂ = 2πR
⇒ R₁ + R₂ = R.