TERMS FOR CIRCLE PROBLEMS

Radius (r): segment drawn between the center of a circle and a point on that circle
Diameter (d): chord that passes through the center of the circle
Chord: segment draw between two points on a circle
Circumference: distance around the entire edge of a circle
Arc: curved section of the outside of a circle
Sector: fractional part of a circle’s area, like a slice of pizza

RULES FOR CIRCLE PROBLEMS

• Area of a Circle = Πr²
• Area of a Sector = n°/360° × Πr²
• Circumference of a Circle = 2Πr     or     Πd

SAMPLE PRACTICE QUESTIONS FOR CIRCLES

1.

If the radius of circle O is 4, then what is the area of sector ST?

      Solution 1: Using Sector Area Formula
      1) Area of Sector = n°/360° × Πr² = 30°/360° × 4r² = 1/12 × 16Π = 4/3Π

      Solution 2: Using a Ratio
      1) Area of Circle =  Πr² --> ⑄² =  16Π

      2) Circle : Sector --> 30°/360° : x/16Π --> 360x = 480Π --> 4/3Π

SAT Math: Circle Problems

Lesson Includes:

—SAT Math Terms for Circle Questions

—Rules for Circle Problems

—Sample SAT Practice Questions

—Practice Questions

Math

SAT Reading

SAT Writing

SAT Vocabulary

CIRCLES MATH QUIZ

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