Circumference of a Circle

Slides:

Advertisements

Similar presentations

M5G2 – Students will understand the relationship of the circumference of a circle, its diameter, and pi (pi ≈ 3.14)

Advertisements

EXAMPLE 1 Use the formula for circumference Find the indicated measures. Write circumference formula. Substitute 9 for r. Simplify. Use a calculator. =

Circumference of a Circle Math 10-3 Ch.3 Measurement.

Area and Circumference of Circles

Lesson 8.1: Perimeter and Circumference

Equations of Circles.

Review Multiplying decimals: 3.2 x 5.12 Multiplying fractions and whole numbers: 5 x 2/3.

Chapter 10 Lesson 1: Circles and Circumference Objective: Learn to find the circumference of circles.

Math Circumference of Circles & Area of Circles. Vocabulary A circle is the set of all points in a plane that are the same distance from a given point,

Circumference & Pi    3.14.

8-1C The Circumference of a Circle What is circumference? What is pi? What is the symbol for pi? What are the formulas for the circumference of a circle?

Circumferences and Areas of Circles COURSE 3 LESSON 8-8 The diameter of a small pizza is 24 cm. Find its area. Round to the nearest tenth. A = r 2 Use.

Perimeter and Circumference

Lesson 6-9 Pages Geometry: Circles and Circumference (and Area) Lesson Check 6-8.

Warm-Up  Multiply.  1.89 x 97  x 76  x 34  4.38 x 28.

Spring 2007Mrs. Bubello Circumference. Spring 2007Mrs. Bubello Circumference Objectives To identify the parts of a circle. To derive a formula for circumference.

Lesson 10-7 Pages Circumference and Area: Circles.

The area of the circle is about 227 m 2. COURSE 2 LESSON 8-4 Find the area of the circle to the nearest unit. = (8.5) 2 Substitute 8.5 for the radius.

Circumference and area of circles Pick up your calculator for today’s notes.

Lesson 7-2 Circumference and Area of Circles. Definitions Circle - A set of points in a plane that are the same distance away from a given point in the.

UNIT 9: GEOMETRY – 6 TH GRADE LESSON 5: AREA OF A CIRCLE.

Circumference and Diameter 1/31/2006. Circumference A circle is a shape with all points the same distance from the center. It is named by the center.

Area and Circumference of Circles. Circumference of a Circle Formula to MEMORIZE!!!! OR.

Chapter 4 L4-5 Notes: Perimeter. Vocabulary The distance around any closed figure is called its perimeter. P for “Plus” all Sides.

Use the formula for circumference

Mrs. Planavsky 4 th Grade.  Find the circumference of a circle  Find the measurement of a diameter of the circle.

Circumference Lesson #33. What is Circumference? The distance around the outside of a circle is called the circumference (essentially, it is the perimeter.

SPI I CAN identify parts of a circle. I CAN find the circumference and area of a circle.

Geometry Honors Section 5.3 Circumference and Area of Circles

Holt CA Course Circles and Circumference Warm Up Warm Up Lesson Presentation California Standards Preview.

8-3 Perimeter and Circumference Course 2 Warm Up Warm Up Problem of the Day Problem of the Day Lesson Presentation Lesson Presentation.

Circle Circle Area of a Circle Area = π r 2. Circle  Circle- is a line forming a closed loop, and every point on which is fixed distance from a center.

Standard Form of a Circle Center is at (h, k) r is the radius of the circle.

AREA OF A CIRCLE Lesson Parts of a Circle Finding the Area Area means the amount of space covered. The symbol is called pi and is approximately.

EOC Practice Question of the Day. Graphing and Writing Equations of Circles.

Introduction & Installation. Circles A circle is a shape with all points the same distance from the center. A circle is named by the center. The circle.

By: Kay McInnis. Diameter DIAMETER is the distance across a circle passing through the center point.

9-1 Perimeter and Circumference Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day Lesson Quizzes Lesson Quizzes.

Parts of a circle The distance around circle O is called the circumference of the circle. It is similar to the perimeter of a polygon.

EQ: How do you find the circumference of a circle? Lesson 4-6 Circumference pp Vocabulary to watch out for this lesson: Circle Center Diameter.

Circumference The distance around a circle or Find the circumference to the nearest tenth

Circles Circumference and Area 6 th Grade Math LaVergne Middle School.

CIRCLES RADIUS DIAMETER (CHORD) CIRCUMFERENCE ARC CHORD.

Objective: Solve equations using area circumference, diameter, and radius.

Do Now:. Circumference What is circumference? Circumference is the distance around a circle.

Circles. Parts of a Circle Center The diameter is the distance across the circle through the center The radius is the distance to the center point.

Holt CA Course Circles and Circumference MG1.1 Understand the concept of a constant such as  ; know the formulas for the circumference and area.

Standard Form of a Circle Center is at (h, k) r is the radius of the circle.

Introduction & Installation. Circles A circle is a shape with all points the same distance from the center. A circle is named by the center. The circle.

CIRCLES AND CIRCUMFERENCE. CONTINUATION OF PI DAY In every circle, the ratio of the circumference to the diameter is equal to …… The Greek letter.

Opening Activity 1. Find the circumference of a circle with a diameter of 8 ft. Round to the nearest tenth. C= 3.14(8)= 25.1 ft 2. Find the circumference.

1)Find the circumference and area of a circle with a diamater of 10 in. Round to the nearest hundredth. Do not forget the units! 2) What would be the radius.

9-1 Perimeter and Circumference. 9-1 Perimeter and Circumference Warm Up Add or multiply. You need to do BOTH of these!

Warm Up Problem of the Day Lesson Presentation Lesson Quizzes.

Preview Warm Up California Standards Lesson Presentation.

Warm up Find each measurement.

Geometry: Circles and Circumference

Circles: Circumference & Area

Circles: Circumference & Area

Perimeter and Circumference

Perimeter and Circumference

Circumference Definition: The distance around a circle. It’s a special word for perimeter. Picture:

Perimeter and Circumference

Insert Lesson Title Here

Unit 2: Ratios and Proportional Relationships

Warm-Up Define the radius, diameter, and circumference of a circle.

Perimeter and Circumference

Circumference and Area of a Circle

Geometry: Circles and Circumference

Warm Up Problem of the Day Lesson Presentation Lesson Quizzes.

Presentation transcript:

Circumference of a Circle

C = 2r C  Circumference - The distance around a circle For every circle, the ratio of circumference C to diameter d is the same. This ratio, , is the Greek letter , called pi. C d Radius 22 7 Pi is approximately equal to 3.14 or . To find Circumference knowing diameter Diameter C = d To find Circumference knowing radius C = 2r Circumference C  To find Diameter use

Find the circumference of the circle to the nearest tenth. Use 3 Find the circumference of the circle to the nearest tenth. Use 3.14 for . EX1) C = d You know the diameter. 12 in. C  3.14 (12) Substitute for  and d. C  37.68 Multiply. EX2) C = 2r 11 cm C  2 (3.14)(11) C  69.08

The circumference of a circle is 56.52, what is the diameter. EX3) The circumference of a circle is 56.52, what is the diameter. Substitute C = d 56.52 = 3.14 d Divide 3.14 on both sides of equation 3.14 3.14 18 = d

The circumference of a circle is 50.24, what is the radius. EX4) The circumference of a circle is 50.24, what is the radius. C = 2r 50.24 = 2(3.14)( r ) 3.14 3.14 16 = 2r 2 2 8 = r

If the diameter or radius of a circle is a multiple of 7, use for p. 22 7 The diameter of a circular pond is 42 m. What is its circumference? Use EX5) for . 22 7 C = d You know the diameter. 22 7 22 7 C  · 42 Substitute for  and 42 for d. 22 7 42 1 C  · Write 42 as a fraction. 6 22 7 42 1 · C  Simplify. 1 C  132 Multiply.

notes

Circumference of a Circle Date _______________ Circumference of a Circle

Pi is approximately equal to ____ or . Circumference - For every circle, the ratio of circumference C to diameter d is the same. This ratio, , is the Greek letter , called pi. C d Pi is approximately equal to ____ or . To find Circumference knowing diameter To find Circumference knowing radius To find Diameter use

Find the circumference of the circle to the nearest tenth. Use 3 Find the circumference of the circle to the nearest tenth. Use 3.14 for . EX1) 12 in. EX2) 11 cm

EX3) The circumference of a circle is 56.52, what is the diameter.

EX4) The circumference of a circle is 50.24, what is the radius.

If the diameter or radius of a circle is a multiple of 7, use for p. Helpful Hint 22 7 The diameter of a circular pond is 42 m. What is its circumference? Use EX5) for . 22 7