Angle formed by each blade = 40°
So, total angle formed by 3 blades
= 40° × 3 = 120°
Total angle of a circle = 360°
Ratio of angle formed by total circle to angle formed by the 3 blades
= 360° : 120°
= 360 : 120
= 3 : 1
Total area of circle
= πr²
= π(3m)²
= π9m²
Let the area of blades be x.
So, area of total circle : x = 3 : 1
= π9m² : x = 3 : 1
= π9m²/x = 3/1
= π9m²/3 = x/1
= π9m²/3 = x
= π3m² = x
So, the area of all three blades is π3m².
