Circumference/area/arc length/sector area Review

Front

What is the formula for the circumference of a circle?

Back

C = πd or C = 2πr, where d is the diameter and r is the radius.

Front

How do you calculate the area of a circle?

Back

A = πr², where r is the radius.

Front

What is the formula for arc length?

Back

Arc Length = (θ/360) × 2πr, where θ is the angle in degrees and r is the radius.

Front

How do you find the area of a sector?

Back

Area of Sector = (θ/360) × πr², where θ is the angle in degrees and r is the radius.

Front

What is the relationship between diameter and radius?

Back

Diameter = 2 × Radius.

Front

If the radius of a circle is 10 cm, what is the circumference?

Back

C = 2π(10) = 62.83 cm.

Front

If the radius of a circle is 5 m, what is the area?

Back

A = π(5)² = 78.54 m².

Front

What is the arc length of a circle with a radius of 12 cm and an angle of 90 degrees?

Back

Arc Length = (90/360) × 2π(12) = 9.42 cm.

Front

How do you convert degrees to radians?

Back

Radians = Degrees × (π/180).

Front

What is the area of a sector with a radius of 8 m and an angle of 45 degrees?

Back

Area of Sector = (45/360) × π(8)² = 11.31 m².