Ex 12.2

Ex 12.2, 1

Ex 12.2, 2

Ex 12.2, 3 Important

Ex 12.2, 4 Deleted for CBSE Board 2022 Exams

Ex 12.2, 5 Important Deleted for CBSE Board 2022 Exams

Ex 12.2, 6 Deleted for CBSE Board 2022 Exams

Ex 12.2, 7 Important Deleted for CBSE Board 2022 Exams

Ex 12.2, 8 Important

Ex 12.2, 9

Ex 12.2, 10

Ex 12.2, 11 Important

Ex 12.2, 12 You are here

Ex 12.2, 13 Important Deleted for CBSE Board 2022 Exams

Ex 12.2, 14 (MCQ)

Last updated at May 29, 2018 by Teachoo

Ex 12.2, 12 To warn ships for underwater rocks, a lighthouse spreads a red coloured light over a sector of angle 80° to a distance of 16.5 km. Find the area of the sea over which the ships are warned. (Use π= 3.14) Radius (r) = 16.5 km 𝜃=80° Area over which ships are warned = Area of sector with angle 80° = 𝜃/(360°)×𝜋𝑟2 = (80°)/360×𝜋 (16.5)2 = 80/360×22/7×16.5×16.5 = 2/9×22/7×165/10×165/10 = 189.97 km2 Hence, Area of sea cover = 189.97 km2