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सी.आई.एस.सी.ई.आईसीएसई ICSE Class 8

In the Following Figure, a Rectangle Abcd Enclosed Three Circles. If Bc = 14 Cm, Find the Area of the Shaded Portion (Take π = 22/7) - Mathematics

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प्रश्न

In the following figure, a rectangle ABCD enclosed three circles. If BC = 14 cm, find the area of the shaded portion (Take π = 22/7)

योग

उत्तर

To calculate the area of the shaded portion, we need to subtract the total area of the three circles from the area of the rectangle.

  • Length of BC (Rectangle's width): 14 cm
  • The three circles are identical, and their diameters fit perfectly along the length of the rectangle (AD).

Thus: Diameter of each circle = `("Length of AD (Rectangle)")/("Number of circles")"`

`= 14/3 = 14/3 cm`

Radius of each circle = `"Diameter"/2 = 14/6 = 7/3 cm`

Step 1: Area of the rectangle

Area of Rectangle = Length × Width = AD × BC.

AD = 14 cm, BC = 14 cm.

Area of Rectangle = 14 × 14 = 96 cm2

Step 2: Total area of the three circles

Area of one circle = πr2.

`r = 7/3 cm, pi=22/7`

Area of one circle `= 22/7xx(7/3)^2=22/7xx49/9=1078/63 cm^2`

Total Area of Circles `= 3xx1078/63 = 3234/63 = 51.33 cm^2`

Step 3: Area of the shaded portion

Shaded Area = Area of Rectangle − Total Area of Circles.

Shaded Area = 196 − 51.33 = 144.67 cm2.

The area of the shaded portion is approximately: 144.67 cm2

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अध्याय 20: Area of a Trapezium and a Polygon - Exercise 20 (D) [पृष्ठ २३५]

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सेलिना Concise Mathematics [English] Class 8 ICSE
अध्याय 20 Area of a Trapezium and a Polygon
Exercise 20 (D) | Q 18 | पृष्ठ २३५

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