Unit 3 Lesson 1-5 Flashcard Review

Front

What is the diameter of a circle?

Back

The diameter of a circle is the distance across the circle through its center, and it is twice the length of the radius.

Front

What is the radius of a circle?

Back

The radius of a circle is the distance from any point on the outside of the circle to the center of the circle.

Front

If a circle has a diameter of 24 cm, what is its radius?

Back

The radius is 12 cm, which is half of the diameter.

Front

What is the relationship between diameter and radius?

Back

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

Front

What is the formula for the circumference of a circle?

Back

The formula for the circumference (C) of a circle is C = πd, where d is the diameter.

Front

How do you calculate the circumference if you know the radius?

Back

If you know the radius (r), the circumference can be calculated using the formula C = 2πr.

Front

What is the value of π (pi) approximately?

Back

The value of π (pi) is approximately 3.14.

Front

What is 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

How do you find the area of a circle if you know the diameter?

Back

To find the area using the diameter, first calculate the radius (r = d/2) and then use the formula A = πr².

Front

What is the relationship between the circumference and area of a circle?

Back

The circumference measures the distance around the circle, while the area measures the space inside the circle.