Question

2. The radii of the inner and outer circumferences of a circular running track are 65 m and 72 m respectively
Find the area of the track.​

Answer 1

Given :

• Radius of inner circular track = r = 65m
• Radius of outer circular track = R = 72m

To find :

Area of track

Formula used :

Area of circle = πr²

Image :

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( For users using app, see attachment )

Solution :

✪ Area of track = Area of outer circle - Area of inner circle

➠ Area of track = πR² - πr²

➠ Area of track = π(72²) - π(65²)

➠ Area of track = π( 5184 - 4225)

➠ Area of track = (22/7 ) × 959

➠ Area of track = 22× 137

➠ Area of track = 3014 m²

ANSWER :

Area of track = 3014 m²

Answer 2

Diagram:-

$\setlength{\unitlength}{1cm}\begin{picture}(0,0)\thicklines\qbezier(2.3,0)(2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,2.121)(0,2.3)\qbezier(-2.3,0)(-2.121,-2.121)(0,-2.3)\qbezier(2.3,0)(2.121,-2.121)(-0,-2.3)\qbezier(1.2,0)(1.121,1.121)(0,1.2)\qbezier(1.2,0)(1.121,-1.121)(0,-1.2)\qbezier(0,-1.2)(-1.121,-1.121)(-1.2,0)\qbezier(-1.2,0)(-1.121,1.121)(0,1.2)\put(-0,0){\vector(-1,0){2.3}}\put(-2,0.2){\bf 72m}\put(-0.8,0.12){\bf 65m}\put(0,0){\circle*{0.13}} \end{picture}$

Given:-

• Radius of Inner circle = 65m
• Radius of Outer circle = 72m

Find:-

• Area of the track

Solution:-

Here, we know that

➮ Area = π(r₂² - r₁²)

where,

• r₁ = 65m
• r₂ = 72m
• π = 22/7

↕ Substituting these values ↕

⇰Area of the track = π(r₂² - r₁²)

⇰Area of the track = 22/7[(72)² - (65)²]

⇰Area of the track = 22/7[5184 - 4225]

⇰Area of the track = 22/7[959]

⇰Area of the track = 22×137

⇰Area of the track = 3014m²

Hence, The area of the track is 3014m²