Area of Circles

Area of Circles

Example #1

​Find the area of the circle.

Example #2

​Find the area of a circle with a diameter of 28 inches.

Math Response

Use question (a.) on p. 624 from your book.

Find the area of a circle with a radius of 3.2 centimeters. Use 3.14 for pi and round to the nearest tenth.

Type answer here

Correct Answer: 32.2

Deg^°

Rad

Example #3

Find the area of the face of the Virginia quarter with a
diameter of 24 millimeters. Use 3.14 and round to the nearest tenth if necessary.

Math Response

Use question (b.) on p. 625.

The bottom of a circular swimming pool with a diameter of 30 feet is painted blue. How many square feet are blue. Use 3.14 for pi and round to the nearest tenth.

Type answer here

Correct Answer: 706.5

Deg^°

Rad

Example #4 - Semicircles

Find the area of the semicircle. Use 3.14 for pi and round to the nearest tenth.

Math Response

Use question (c.) on p. 625.

Find the approximate area of a semi circle with a radius of 6 centimeters.

Type answer here

Correct Answer: 56.5

Deg^°

Rad

Class Practice

Open your book to p. 626 - 627. The next few problems will hop around on those two pages. Make sure you are writing the formula and showing your work!

Math Response

#3 on p. 626

Find the area of circle with diameter of 16 meters. Use 3.14 for pi and round to the nearest tenth.

Type answer here

Correct Answer: 201

Deg^°

Rad

Math Response

#11 on p. 627

Find the area of the given semicircle. Use 3.14 for pi and round to the nearest tenth.

Type answer here

Correct Answer: 163.3

Deg^°

Rad

Math Response

Use question #2 on p. 627

Find the area of the given circle. Use 3.14 for pi and round to the nearest tenth.

Type answer here

Correct Answer: 2461.8

Deg^°

Rad

Math Response

Use question #12 on p. 627.

The tunnel opening shown is a semicircle. Find the area, to the nearest tenth, of the opening of the tunnel enclosed by the semicircle.

Type answer here

Correct Answer: 207.6

Deg^°

Rad