Find the area of a circle given the diameter - Online tutor - free Math videos

The video tutorial explains how to find the area of a circle. It introduces key terms like diameter and radius, and explains the concept of π as a ratio of the circle's diameter. The tutorial demonstrates how to calculate the area using the formula A = πR², emphasizing the importance of leaving answers in terms of π for precision. The example provided uses a diameter of 8, resulting in a radius of 4, and calculates the area as 16π.

What is the term used to describe the distance across a circle?

• Chord

• Circumference

• Radius

• Diameter

Which of the following best describes π in relation to a circle?

• A constant value of 2.14

• A ratio of the circle's circumference to its diameter

• The distance from the center to the edge of the circle

• A variable that changes with the circle's size

Why is π considered an irrational number?

• It has a finite decimal representation

• It can be expressed as a fraction

• It is a whole number

• It has a non-repeating, infinite decimal expansion

If the diameter of a circle is 8, what is the radius?

• 2

• 4

• 8

• 16

How is the area of a circle calculated using its radius?

• π times the diameter

• π times the radius

• π times the diameter squared

• π times the radius squared