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सी.आई.एस.सी.ई.आईसीएसई ICSE Class 8

Find the Area of a Flat Circular Ring Formed by Two Concentric Circles (Circles with the Same Centre) Whose Radii Are 9 Cm and 5 Cm.

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प्रश्न

Find the area of a flat circular ring formed by two concentric circles (circles with the same centre) whose radii are 9 cm and 5 cm.

योग
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उत्तर

External radius, r= 9 cm

Internal radius, r2 = 5 cm

Area of ring = `pir_1^2 - pir_2^2`

= `pi(r_1^2 - r_2^2)`

= `pi(9^(2) - 5^(2))`

= `22/7[81 - 25]`

= `22/7 xx 56`

= 176 cm2

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अध्याय 22: Area of a Trapezium and a Polygon - Exercise 20 (D) [पृष्ठ २३४]

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सेलिना Concise Mathematics [English] Class 8 ICSE
अध्याय 22 Area of a Trapezium and a Polygon
Exercise 20 (D) | Q 5 | पृष्ठ २३४

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