Area of circles
for 8th grade
Using the formula A = πr² calculate the area of the given circles to 2 decimal places
Calculate the area of circles
Given the radius or diameter of a circle, we can calculate it's area.
Given a radius r, the area of a circle is calculated as:
Area = π x Radius²
Given a diameter d, the area of a circle is calculated as:
Area = π x (Diameter/2)²
For instance, if we have a circle with a radius of 1 mm, the area A of the circle to two decimal places will be:
A = π x 1² = 3.14 mm²
If we have a circle with a diameter of 12 cm, the area A of the circle to two decimal places will be:
A = π x (12/2)² = π x 36 = 113.10 cm²
Below is a table showing the first 6 question answer pairs for the topic "Area of circles" as used in the lessons for this topic. Our games and tests for the topic use these 6 items plus 10 additional question answer pairs.
The topic "Area of circles" is in the category Geometry & measures for 8th grade (ages 13 to 14).
Revise 'Area of circles' with one of our games for 8th grade
Each of our math topics for secondary are made up of between 6 and 20 question and answer pairs (both the written form and a robot voice speaking those questions and answers). Each topic can be used with all the activities on the site.
Number * Algebra * Ratio proportion rate * Geometry & measures * Probability * Statistics *
