Question

Q4. Find the radius of a wheel if its circumference is 132cm. *

Answer 1

$\huge\tt\colorbox{lime}{Answer}$

Wheel is in the shape of a circle.

Circumference = 132 cm

radius = r = ?

Circumference of circle = 2πr

132 = 2 × 3.14 × r

132 = 6.28 × r

r = 132÷ 6.28

r = 21.01 cm

Answer 2

AnswEr :

• The radius of a wheel = 21 cm

Explanation :

We are given with the circumference of a wheel, that is,

• Circumference of wheel = 132 cm.

We have to find out the radius of a wheel.

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Now,

Let us assume that, the radius of a wheel is x cm.

Diagram :

$\setlength{\unitlength}{1cm}\begin{picture}(0,0)\thicklines\qbezier(2.3,0)(2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,-2.121)(0,-2.3)\qbezier(2.3,0)(2.121,-2.121)(-0,-2.3)\put(0,0){\line(1,0){2.3}}\put(0.5,0.3){\bf\large x cm}\end{picture}$

As we are given with circumference of a wheel. We know that wheel is always is in the form of circle.

We know that, if we are given with circumference of circle we have the required formula, that is,

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→ Circumference of circle = 2πr.

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Substituting the given values in the formula,

⇒ 132 = 2 × 22/7 × x

⇒ 132 × 7 = 2 × 22 × x

⇒ 924 = 2 × 22 × x

⇒ 924 = 44 × x

⇒ 924 = 44x

⇒ 924 - 44x = 0

⇒ -44x = 0 - 924

⇒ -44x = -924

⇒ 44x = 924

⇒ x = 924/44

⇒ x = 21

Hence, the radius of a wheel is 21 cm.

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Verification :

⇒ Circumference of circle = 2πr

⇒ 132 = 2 × 22/7 × 21

⇒ 132 = 2 × 22 × 3

⇒ 132 = 44 × 3

⇒ 132 = 132

Clearly, LHS = RHS

Here both the conditions satisfy, so our answer is correct$.$

Hence Verified !