Circumference and Perimeter of Circles

The video tutorial covers the concept of Pi, its significance as the ratio of a circle's circumference to its diameter, and its representation as a non-terminating, non-repeating decimal. It explains the formulas for calculating the circumference of a circle using Pi, and provides exercises to practice these calculations using both exact and approximate values of Pi. The tutorial also covers the calculation of the perimeter of a semicircle.

What is the value of Pi commonly approximated as?

• 3.13

• 3.12

• 3.14

• 3.15

What is the significance of the number Pi in mathematics?

• It is a whole number

• It is a non-terminating, non-repeating decimal

• It is a fraction

• It is a negative number

Which formula represents the circumference of a circle using its diameter?

• C = 2πd

• C = πr²

• C = πd

• C = 2πr

If the diameter of a circle is 21 cm, what is its circumference using 22/7 as Pi?

• 66 cm

• 70 cm

• 63 cm

• 68 cm

How do you calculate the circumference of a circle when given the radius?

• C = πd

• C = 2πr

• C = πr²

• C = 2πd

What is the circumference of a circle with a radius of 11.7 cm using 3.14 for Pi, rounded to the nearest tenth?

• 73.5 cm

• 74.5 cm

• 76.5 cm

• 75.5 cm

Using the Pi button on a calculator, what is the circumference of a circle with a radius of 11.7 cm, rounded to the nearest hundredth?

• 75.49 cm

• 75.50 cm

• 75.52 cm

• 75.51 cm

What is the formula for the circumference of a semicircle?

• C = πd/2 + d

• C = 2πr

• C = πd

• C = πr²

How do you calculate the perimeter of a semicircle with a diameter of 8 cm using 3.14 for Pi?

• 20.56 mm

• 20.56 m

• 20.56 km

• 20.56 cm

What additional step is needed when calculating the perimeter of a semicircle?

• Subtract the radius

• Multiply by 2

• Divide by 2

• Add the diameter