1 / 12

d = ______ r = ______

radius. diameter. 12 in. 6 cm. Learning Objective Name ___________________________ Today, we will determine 1 the formulas for the circumference and area of a circle. 1 figure out. CFU What are we going to do today? What does determine mean? Determine means _______.

elata
Download Presentation

d = ______ r = ______

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. radius diameter 12 in 6 cm Learning ObjectiveName ___________________________ Today, we will determine1 the formulas for the circumference and area of a circle. 1 figure out CFU What are we going to do today? What does determine mean? Determine means _______. Activate (or provide) Prior Knowledge What is the diameter and radius of the circles below. Teacher Student d = ______ r = ______ d = ______ r = ______ 3 cm 12 in 6 in 6 cm CFU Students, you already know how to find the diameter and the radius of a circle. Today, we will use the diameter and the radius of a circle to determine the formulas for the circumference and area of a circle.

  2. radius diameter circumference 15 in 3 ft Go To Skill Dev #1 Circumference (C) Formulas Using the diameter (d) Using the radius (r) A tire has a diameter of 15 inches. A rug has a radius of 3 feet. The distance around the rug is 18.84 ft. The distance around the tire is 47.1 in. CFU Chan is creating a circular garden. He wants to build a fence around the garden. Explain why he needs to find the circumference. In your own words, what is the circumference of a circle? The circumference of a circle is ________. A fence goes around the garden.

  3. area radius diameter 3 ft Go To Skill Dev #2 Concept Development (continued) The area of a circle is the space inside the circle. • Area is always written as units squared (in², cm²). A formula is an equation that declares the relationship between two or more quantities. • Formulas are used to find measurements, such as the area of a circle. • p is used in the formula for the area of a circle. Area Formula: A rug has a radius of 3 ft. The rug takes up 28.26 ft² of space. CFU Chan is creating a circular garden. He wants to add soil to the garden. Explain why he needs to find the area of the garden. In your own words, what is the area of a circle? The area of a circle is _______________________. Soil goes inside the garden.

  4. Concept Demonstration The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. c i r c u m f e r e n c e Area CFU What is the difference between the circumference and area of a circle?

  5. Circumference Formula Area Formula 8 cm C = pd C = p 2 r A = pr 2 Go To Concept 9 in. Skill Development/Guided Practice 1 The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify4 the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine5 the correct formula to find the measurement. (write on the line) Step #3: Substitute6 the given value into the formula.Remember to double the radius or halve the diameter, if necessary. 4 find (synonym) 5 figure out 6 replace (synonym) CFU (#2) How did I/you determine the correct formula?

  6. Circumference Formula Area Formula C = pd C = p 2 ● r A = pr 2 4 in. 8 in. Skill Development/Guided Practice 2 The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine the correct formula to find the measurement. (write on the line) Step #3: Substitute the given value into the formula.Remember to double the radius or halve the diameter, if necessary. CFU (#2) How did I/you determine the correct formula?

  7. Relevance The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Tyrone is buying a new tire for his bike. He needs to measure the circumference of the tire but all he has is a wooden yardstick. How can he find the circumference of the tire? Tyrone could measure the diameter of the tire and use the formula to solve for circumference. • Determining the formulas for the circumference and area of a circle will • help you with measuring circular distance. 2. Determining the formulas for the circumference and area of a circle will help you do well on tests. CFU Does anyone else have another reason why it is relevant to determine the formulas for the circumference and area of a circle? (pair-share) Why is it relevant to determine the formulas for the circumference and area of a circle? You may give me one of my reasons or one of your own. Which reason is more relevant to you? Why?

  8. Circumference Formula C = pd C = p 2 ● r Area Formula A = pr 2 4 ft 14 in The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Skill Closure Determine the formulas for the circumference and area of a circle. Constructed Response Closure Gary is replacing the leather cover on a stool. What measurement could he find so that the new leather cover is the same size as the old one? How do you know? __________________________________________________________________________________________________________________________________________________________ Summary Closure What did you learn today about determining the formulas for the circumference and area of a circle? Day 1 _________________________________________________________________________________________________ Day 2 _________________________________________________________________________________________________

  9. Independent Practice Name __________________________ The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Area Formula Circumference Formula C = pd C = p 2 r A = pr 2 6 cm Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine the correct formula to find the measurement. (write on the line) Step #3: Substitute the given value into the formula.Remember to double the radius or halve the diameter, if necessary. 14 ft.

  10. Area Formula Circumference Formula C = pd C = p 2 r A = pr 2 14 in. Periodic Review 1 Name ___________________________ The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. 26 cm Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine the correct formula to find the measurement. (write on the line) Step #3: Substitute the given value into the formula.Remember to double the radius or halve the diameter, if necessary.

  11. Periodic Review 2 Name ___________________________ The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Area Formula Circumference Formula C = pd C = p 2 r A = pr 2 18 cm 9 in. Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine the correct formula to find the measurement. (write on the line) Step #3: Substitute the given value into the formula.Remember to double the radius or halve the diameter, if necessary.

  12. Periodic Review 3 Name ___________________________ The circumference of a circle is the distance around the circle. The area of a circle is the space inside the circle. Area Formula Circumference Formula 40 cm C = pd C = p 2 r A = pr 2 16 in. Determine the formulas for the circumference and area of a circle. Step #1: Read the problem. a: Identify the given measurement. (underline) b. Identify the measurement that needs to be found. (circle) Step #2: Determine the correct formula to find the measurement. (write on the line) Step #3: Substitute the given value into the formula.Remember to double the radius or halve the diameter, if necessary.

More Related