What are the important formulas for a circle

The video tutorial covers the topic of circles, starting with an introduction and basic definition. It explains that a circle is a set of points equidistant from a center point, with the radius being the distance from the center to any point on the circle. The diameter is the distance across the circle, and the circumference is the distance around it. Basic formulas for calculating the area and circumference are discussed, including the use of π (pi) and its approximation as 3.14. The tutorial emphasizes using the full value of π for calculations.

What is the definition of a circle?

• A shape with no angles

• A polygon with three sides

• A set of points equidistant from a fixed point

• A shape with four equal sides

What is the term used for the distance across a circle through its center?

• Diameter

• Circumference

• Radius

• Chord

Which formula represents the circumference of a circle?

• 2πr

• r²

• πr²

• πd

What is the formula for the area of a circle?

• πd

• r²

• πr²

• 2πr

What is the approximate value of π often used in calculations?

• 4.13

• 3.14

• 2.71

• 1.62