One blade cleans a sector of radius 28 cm and angle 120°: (120/360) x (22/7) x 28² = 2464/3 cm². With two blades, total cleaned area is 2 x (2464/3) = 4928/3 = 1642.67 cm².
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Using sector area formula (θ / 360) x π x r² with r = 7 cm and θ = 60° gives (60 / 360) x (22/7) x 7² = (1/6) x 154 = 77/3 = 25.67 cm².
Let shorter diagonal be d, so longer diagonal is 2d. Area of rhombus is (1/2) x d1 x d2 = (1/2) x d x 2d = d². Equating d² = 128 gives shorter diagonal d = √128 = 8√2 cm ...
In rectangle ABCD, base AD = 8 cm and perpendicular height from vertex E to AD is 10 cm. The area of triangle ADE is (1/2) x base x height = (1/2) x 8 x 10 = 40 cm².
Arc length is (75/360) x 2 x (22/7) x 14 = (5/24) x 88 = 55/3 = 18.33 cm. Sector perimeter equals arc length plus two radii: 18.33 + 28 = 46.33 cm (or 46 and 1/3 cm).