ps is a diameter of a circle of radius 6 cm Q and r are points on the diameter that diameter that PQ ,QR and RS are equal . semicircle are drawn with PQ and QS as diameter , as shown in the adjoining figure . find the perimeter of the shaded region also find the area of the shaded region
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Answer:
A river valley civilization is an agricultural nation or civilization situated beside and drawing sustenance from a river. A "civilization" means a society with large permanent settlements featuring urban development, social stratification, specialization of labor, centralized organization, and written or other formal means of communication. A river gives the inhabitants a reliable source of water for drinking and agriculture. Additional benefits include fishing, fertile soil due to annual flooding, and ease of transportation. The first great civilizations, such as those in Mesopotamia, Harappa and Ancient Egypt, all grew up in river valleys. Tigris River flourished near Mesopotamia civilization and river nile flourished near civilization of Egypt.
ps = 12 cm
⇒pq = qr =rs
∴ pq =qr =rs = 1/3 x ps = 1/3 x 12 = 4 cm.
qs = 2 pq
qs = 2 x 4 = 8 cm
∴ area of shaded region = area of semicircle with ps as diameter + area of semicircle with pq as diameter – area of semicircle with qs as diameter
= 1/2 [ 3.14 x 6² + 3.14 x 2² - 3.14 x 4² ]
= 1/2 [ 3.14 x 36 + 3.14 x 4 – 3.14 x 16 ]
= 1/2[ 3.14 ( 36 + 4 – 16)]
= 1/2 ( 3.14 x 24 ) = 1/2 x 75.36
∴ area of shaded region = 37.68 cm²
Perimeter of shaded region=12*22/7 =264/7