Area and Circumference of Circles

The video tutorial covers lesson 17, focusing on solving geometry problems. It begins with calculating the radius of a circle using its circumference and pi. The lesson then moves to finding the area of a rectangle and solving for unknown dimensions. It explains how to approximate the area of a circle by rearranging it into a rectangle. The tutorial also includes practical problems like calculating the area covered by a sprinkler and determining waste from cutting a circular table from a square piece of wood.

If the circumference of a circle is 37.68 and pi is approximated as 3.14, what is the estimated radius of the circle?

• 7 inches

• 6 inches

• 8 inches

• 5 inches

What is the area of a rectangle with a length of 6 cm and a width of 4 cm?

• 24 cm²

• 20 cm²

• 28 cm²

• 32 cm²

Given a rectangle with an area of 27 cm² and a width of 3 cm, what is the length of the rectangle?

• 8 cm

• 7 cm

• 9 cm

• 10 cm

How can you approximate the area of a circle by rearranging it into another shape?

• Triangle

• Hexagon

• Square

• Parallelogram

What is the formula for the area of a circle?

• pi r

• pi d

• pi r²

• 2 pi r

If you count squares to estimate the area of a circle, what fraction of the circle can you count to simplify the process?

• One-fifth

• One-fourth

• Half

• One-third

What is the estimated area of a circle with a radius of 10 cm using the square counting method?

• 360 cm²

• 340 cm²

• 320 cm²

• 300 cm²

A sprinkler covers a circular area with a radius of 12 feet. What is the approximate area covered?

• 550 ft²

• 500 ft²

• 452 ft²

• 400 ft²

If a circular table is cut from a square piece of wood with a radius of 3 feet, what is the estimated waste area?

• 8.74 ft²

• 6.74 ft²

• 7.74 ft²

• 5.74 ft²

What is the diameter of a circle if its radius is 3 feet?

• 12 feet

• 3 feet

• 6 feet

• 9 feet