Circles: Arc Length and Sector Area

Front

What is the formula for the area of a circle?

Back

A = πr², where r is the radius.

Front

What is the area of a circle with a diameter of 10 cm?

Back

78.5 cm²

Front

What is a diameter?

Back

A diameter is a line segment that passes through the center of a circle and has its endpoints on the circle.

Front

What is the formula for arc length?

Back

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

Front

What is the formula for the area of a sector?

Back

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

Front

If the radius of a circle is 6 inches and the central angle is 100°, what is the area of the shaded sector?

Back

10π

Front

What is the relationship between the radius and diameter of a circle?

Back

The diameter is twice the radius (d = 2r).

Front

What is the circumference of a circle?

Back

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

Front

How do you find the area of a shaded region in a circle?

Back

Subtract the area of the unshaded part from the total area of the circle.

Front

What is the measure of a full circle in degrees?

Back

360 degrees.