Question

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 seaover which the ships are warned. (Use π = 3.14)​

Answer 1

Solution:-

Let O bet the position of Lighthouse.

Here the radius will be the distance over which light spreads.

Given:

• Radius (r) = 16.5 km
• Sector angle (θ) = 80°

Now, the total area of the sea over which the ships are warned = Area made by the sector

Or, Area of sector = (θ/360°) × π r²

= (80°/360°) × π r² km²

= 189.97 km²

Answer 2

Step-by-step explanation:

When a lighthouse spreads a red colored light under water , it forms a sector of angle 80° and radius = 16•5 km

Therefore, Area of sector = theta / 360 × pi ×r^2

Area of sector =80/360 × 3•14×16•5×16•5

= 189•97 km^2