Areas Related to Circles - Flash Cards
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What is a sector of a circle?
A sector is the portion of a circular region enclosed by two radii and the arc connecting them.
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What is a segment of a circle?
A segment is the area enclosed between a chord and the arc of the circle.
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What are minor and major sectors?
The minor sector is the smaller area cut off by the chord, while the major sector is the larger area.
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What are minor and major segments?
The minor segment is the smaller area between a chord and the arc, while the major segment is the larger area.
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What is the formula for the area of a sector?
Area of a sector = (πrq) / 360, where 'r' is the radius and 'q' is the angle in degrees.
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What is the formula for the length of an arc?
Length of an arc = (2πrq) / 360, where 'r' is the radius and 'q' is the angle in degrees.
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How to calculate the area of a segment?
Area of a segment = Area of the sector - Area of the triangle formed by the radii and chord.
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What is a common mistake in finding areas?
Confusing the area of a sector with the area of a segment is a common mistake.
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How do you convert degrees to radians?
To convert degrees to radians, multiply by (π/180).
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How can you find the area of a quadrant from the circumference?
Use the formula for the area of a quarter circle: A = (πr²)/4 where r = circumference/(2π).
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How do you find the area of the triangle in a sector?
Use the formula: Area = (1/2) * base * height, with the base being the chord length.
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What is the formula for the total area of a circle?
Total Area = πr², where 'r' is the radius.
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How to find the area of the major sector?
Area of major sector = Total area of circle - Area of minor sector.
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What value of π should be used?
Unless stated, use π = 3.14 or π = 22/7 depending on the problem.
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How to find the area swept by a clock hand?
Area = Sector area = (θ/360) * πr², where θ is the angle swept by the hand.
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What is a quadrant of a circle?
A quadrant is a sector that represents 90 degrees of the circle.
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How to find the length of a chord?
Use the formula: Chord Length = 2r * sin(θ/2) where r is the radius and θ is the angle.
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Why is π important?
π is essential for calculations involving circles, representing the ratio of circumference to diameter.
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