Topic Details (Notes format)

How to Calculate the Area of a Circle

Subject: Mathematics

Book: Maths Mastery

The area of a circle is given by the formula A = πr², where r is the radius—the distance from the center to the circumference. If you have a circle with radius 5 cm, its area is π × 5² = 25π cm². In practical terms, you might need to measure the space a circular rug covers or the cross-sectional area of a circular pipe. Knowing how to apply A = πr² is foundational in geometry, engineering, and architecture. Pairing this knowledge with circumference or volume formulas further expands your capability to handle circular shapes in diverse projects and daily scenarios.

Practice Questions

The sum of the squares of two consecutive integers is 145. What are the integers?

View Question

If the product of two numbers is 120 and their sum is 26, what are the numbers?

View Question

How many ways can 4 people sit in a row?

View Question

What is the area of an equilateral triangle with side length 10 cm?

View Question

If two complementary angles differ by 30°, what are the angles?

View Question

If log(100) = 2 and log(10) = 1, what is log(1000)?

View Question

If 5x - 2 = 13, what is the value of x?

View Question

The probability of getting an even number when rolling a die is:

View Question

A number is increased by 20% and then decreased by 10%. What is the net change?

View Question

A sphere has a radius of 7 cm. What is its volume?

View Question