can someone help me to find the sector of a circle ?
回答 (7)
Area of sector
= (Area of circle) × [(Angle at center)/360°]
= π × Radius² × [(Angle at center)/360°]
= π × (6 ft)² × (120/360)
= 12π ft²
≈ 12 × 3.14 ft²
= 37.68 ft²
Area of Sector = 120°/360° * area
= 1/3 * pi * 6^2
= 12π ft^2
the sector is ⅓ of the circle
area of = ⅓ area of circle = ⅓π6² = 12π ft²
In general, a sector of a circle is subtended by a central angle x, say. 3 equal ratios result.
(sector arc)/(circle circumference) = (sector area)/(circle area) = [(x deg./360 deg.) or (x rad/2pi*rad)]. Now in
our problem, circle radius = r, say, = 6 ft. x = 120 deg. Then (120 deg./360 deg.) = (1/3). Now circle circumference = 2pi*r = 2pi*6 ft = 12pi*ft and sector arc = 12pi*ft(1/3) = 4pi*ft. Circle area = pi*r^2 = 36pi*ft^2
Then sector area = (1/3)circle area = (1/3)36pi*ft^2 = 12pi*ft^2.
Area of sector = 1/2 r^2θ, where θ is in radians
= 1/2(6)(2π/3)
= 2π ft^2 ............[ = 6.283165307 ft^2]
What do you want to know about it?
Area? Since 120° is 1/3 of 360°, the area of the shaded sector is 1/3 the area of the circle; πr²/3 = 12π ft²
Arc Length? Since 120° is 1/3 of 360°, the arc length of the shaded sector is 1/3 the circumference of the circle: 2πr/3 = 4π ft
Perimeter? Perimeter of the shaded sector is the arc length + twice the radius = 4π+12 ft
Something else? You'll have to tell us what you want.
收錄日期: 2021-05-01 14:16:36
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