Calculating Circumference

Slides:

Advertisements

Similar presentations

Problem 7.4 Remember: A radius square is a square whose sides are the same length as the radius of the circle.

Advertisements

Pi Day! Squaring the Circle Goals for today’s lesson: Estimate Π Practice finding the perimeter of squares. Practice finding the perimeter (circumference)

Lesson 16: The Most Famous Ratio of All

Joseph A. Castellano, Ph.D.

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

By Maria Bocanegra. The distance around a closed curved circle. WHAT IS CIRCUMFERENCE?

Circumference of a Circle Lesson Perimeter the perimeter is the distance around a figure.

Circles: Area and Circumference. Definitions Circumference: Distance around the outside of a circle Area: How many squares it takes to cover a circle.

Name ______ Gr.__ Lesson 4.2 – Circumference of a Circle Jan.__ Objective: to investigate the relationship between the circumference and diameter of a.

CIRCUMFERENCE OF A CIRCLE LEARNING TARGET 4: I CAN SOLVE PROBLEMS USING AREA AND CIRCUMFERENCE OF A CIRCLE.

  investigate the relationship between the diameter and circumference of a circle.

Place a piece of string round the circle and then open it out flat:

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

(7.4) Patterns, relationships, and algebraic thinking. The student represents a relationship in numerical, geometric, verbal, and symbolic form. The student.

Circles & Circumference Standard Math The circumference is the distance around a circle. Circumference Circumference is the perimeter of circles. Radius.

1)Create a circle with a diameter of 6 cm. 2) Using a ruler, divide the circle into 8 congruent sectors. 3)Cut out the sectors and arrange them to form.

Circles and Circumference. Vocabulary A circle is a plane figure that consists of a set of points that are equidistant from a given point called the center.

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?

7.9A Estimation and Measurement

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.

Is there anything invariant about circles?. Bell Ringer CDCD Compare the ratio of the circumference to the diameter C = 9.42 D = 3 C =

Perimeter Perimeter is the distance all of the way around an object and is find by adding the lengths of all of the sides together.

Circumference Review. Review What is the relationship between a radius and a diameter? What does a circumference measure? What formulas do we use to calculate.

Diameter Radius.

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

Estimating the Area of a Circle Math 8 Stewart COPY SLIDES THAT HAVE A PENCIL.

Circles: Circumference What do we call the measure of the perimeter of a circle or the distance around a circle? circumference.

CIRCLES RADIUS DIAMETER (CHORD) CIRCUMFERENCE ARC CHORD.

Warm-up Inside Out Powerpoint Surrounding A Circle Guided Practice Finding Circumference Independent Practice How Do I Find It? Measurement.

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

Opening Activity 1. What is the area of a rectangle with a length of 5 inches and a width of 12 inches? (Remember: A=lw) A=lw A=(5)(12) 2. What is the.

Measurement: Circles and Circumference With Mr. Minich

Warm up Find each measurement.

Geometry: Circles and Circumference

Objectives Develop and apply the formulas for the area and circumference of a circle. Develop and apply the formula for the area of a regular polygon.

Geometry: Circles and Circumference

Circles Circles are EVERYWHERE..

Measurement Warm-up Stringing Lights Powerpoint Squaring a Circle

Measurement π Discovering Pi

Shape and Space Circles The aim of this unit is to teach pupils to:

Circles Bingo Aim: Full House.

Circles: Circumference & Area

Check your understanding!

Shape and Space Circles The aim of this unit is to teach pupils to:

Quadrilateral Review Measure the length and width of your desktop.

Circles: Circumference & Area

Circles and Circumference

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

Choose a shape and write down everything you know about it.

Unit 2: Ratios and Proportional Relationships

Geometry: Circles and Circumference

11.4 Circumference and Arc Length

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

Objective Apply formulas for perimeter, area, and circumference.

Find the Circumference of a Circle

The properties of a circle and how you can identify it.

DO NOW Complete number 6 (Area and Perimeter) on sheet 6-8.

Happy Friday!!! Please take out some paper to take notes on today lesson. Be ready to begin class when the bell rings.

Finding area of circle using circumference

G26 Circumference and area of a circle

Perimeter and Circumference

Circumference and Area: Circles

Topic: How to calculate the area of a circle.

Area of Circle.

Geometry: Circles and Circumference

Presentation transcript:

Calculating Circumference

Circumference Defined Circumference is the boundary of a circle or the length of this boundary.

Copy the following chart in your Notes: Circumference (cm) Diameter Circumference ÷ Diameter (cm) (to two decimal places) Radius Circumference ÷ radius (cm) Circle 1 Circle 2 Circle 3 Draw 3 circles of random size on the chart paper provided. Measure the circumference of each (using string) and record Measure the diameter* of each and record. Complete the last 3 columns of the table.

Do you Notice Any Patterns?

Do you Notice Any Patterns? Circumference ÷ diameter was always really really close to 3. This shows that approximately 3 diameters will equal the circumference

Online Activity Google Search Ontario Education Resource Bank Search activity # ELO1476960 Click content, click next, click “Pi, Please with a side of a baseball” (this is your activity) The next slide will let you know what to do as you work through the learning experience

Pi Please, with a Side of Baseball Record the diameter and circumference of each of the 3 objects (the puck, the golf ball and the pop can) What is the relationships between diameter and circumference? Write the symbol for pi, the numerical value of pi, and a definition of pi Copy and complete question 5

Reflection Questions: Do you notice any patterns? How would you calculate the circumference of a circle if you knew only its radius? If you knew the circumference of a circle, how would you estimate its diameter? Why would you use a formula to determine the circumference of a circle, rather than measuring the circumference?

Pi (π) Pi (π) is the ratio of the circumference to the diameter or the number of times the diameter of a circle divides the circumference. Its value is 3.141 592 654… or about 3.14, rounded to two decimal places. The formula for the circumference (C) of a circle with diameter (d) is C = πd The formula for the circumference of a circle with radius (r) is C = 2 πr