Circumference, Area, Sector Area and Arc Length Flashcard

Front

What is the formula for the circumference of a circle?

Back

The circumference (C) of a circle is given by the formula C = 2πr, where r is the radius.

Front

How do you calculate the area of a circle?

Back

The area (A) of a circle is calculated using the formula A = πr², where r is the radius.

Front

What is the formula for the area of a sector of a circle?

Back

The area of a sector (A) is given by A = (θ/360) * πr², where θ is the angle in degrees and r is the radius.

Front

How do you find the length of an arc in a circle?

Back

The length of an arc (L) is calculated using the formula L = (θ/360) * 2πr, where θ is the angle in degrees and r is the radius.

Front

What is the value of π (pi)?

Back

π (pi) is approximately equal to 3.14 and is the ratio of the circumference of a circle to its diameter.

Front

If the radius of a circle is 5 units, what is its circumference?

Back

Using the formula C = 2πr, the circumference is C = 2π(5) = 10π units.

Front

If the radius of a circle is 7 units, what is its area?

Back

Using the formula A = πr², the area is A = π(7)² = 49π square units.

Front

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

Back

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

Front

How do you convert degrees to radians?

Back

To convert degrees to radians, multiply by π/180.

Front

What is the formula for the area of a circle in terms of diameter?

Back

The area (A) can also be expressed as A = (π/4)d², where d is the diameter.