# 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 concepts related to 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 with a 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 and angle with degree measure 80°

= θ/360° × πr^{2}

= 80°/360° × πr^{2}

= 2/9πr^{2}

= 2/9 × 3.14 × 16.5 km × 16.5 km

= 189.97 km^{2}

**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

### NCERT Solutions Class 10 Maths - Chapter 12 Exercise 12.2 Question 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

The area of the sea over which the ships are warned by the lighthouse for underwater rocks is 189.97 km^{2}.