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)

Solution:

We use the area of a sector of a circle to solve the given question.

The lighthouse spreads red coloured light over a sector of a circle with a radius 16.5 km and an angle of degree measure 80°

Area of the sea over which the ships are warned = Area of the sector of the circle with radius 16.5 km with an angle of degree measure 80°

= θ/360° × πr²

= 80°/360° × πr²

= 2/9πr²

= 2/9 × 3.14 × 16.5 km × 16.5 km

= 189.97 km²

☛ Check: NCERT Solutions Class 10 Maths Chapter 12

Video Solution:

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)

NCERT Solutions Class 10 Maths Chapter 12 Exercise 12.2 Question 12

Summary:

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. The area of the sea over which the ships are warned is 189.97 km².

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