Area of Circle.

Slides:

Advertisements

Similar presentations

The area of a circle is the amount of space inside the circle. Area is always written as units squared (in², cm²). A formula is an equation that declares.

Advertisements

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

Diameter  Any line segment that passes through the center of the circle and has endpoints on the circle.

Radius The distance from the center of a circle to any point on the circle. M A point on the circle Center.

Mean 1/15/2015. Do Now! Day 2 Grab your notebook and folder from your cubby Look back at your notes from yesterday and answer the following in your notebook:

2. We will solve problems for the area and circumference of a circle.

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

Circles. A circle is a shape with all points the same distance from its center. The distance around a circle is called its circumference. The distance.

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

Definition: A circle is the set of all points on a plane that is a fixed distance from the center.

Perimeter Rectangles, Squares, and Triangles Perimeter Measures the distance around the edge of any flat object. To find the perimeter of any figure,

Missing Sides + Perimeter Find & Add. Take your notebook and folder from your cubby. Then find the MISSING SIDE LENGTHS and PERIMETER for each of the.

Area and Circumference of Circles

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

CIRCUMFERENCE OF CIRCLES. What is the definition of a circle? A flat shape whose points are all the same distance away from the center This distance from.

3.4 Area and Circumference 1 Circle A circle is a plane figure that consists of all points that lie the same distance from a fixed point. The fixed point.

Objectives: Students will use a ruler to measure diameters of circles and then find area and circumference of circles. M11.C.1.

Lesson 8.1: Perimeter and Circumference

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

Circumference & Area of Circles Unit 5-3. Circumference Formula for Circumference: ** r is the radius ** ** 2r = d. d is the diameter. ** **Circumference.

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,

Do Now C = π x D; D = 2R; R = ½ D. Find the 1). Radius if the Diameter is 8 miles 2). Diameter if the Radius is 12 inches 3). The circumference if the.

Pi Video. Vocabulary 1. Circle – a set of points equidistant from a given point. 2. Center- a given point from which all points are the same distance.

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

Lesson 10-7 Pages Circumference and Area: Circles.

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.

1.What is the probability of rolling dice twice and getting a 4 and then a 7? Are these independent or dependent? 2.If you choose two cards from a deck,

Do Now: Solve 5 + 2[(92 – 4) + (23 + 1)] Solve and graph x + 11>25

Circles: Circumference & Area Tutorial 8c A farmer might need to find the area of his circular field to calculate irrigation costs.

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

Splash Screen Example 9-2b Objective Find the circumference of circles.

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

Warm-Up Find the area: Circumference and Area Circles.

Splash Screen. Over Lesson 11–6 5-Minute Check 1.

Danielle Camporese Circumference, Diameter, Radius, Oh My!

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

Bell Work Find the circumference of the circles.

Circles M5G2: Students will understand the relationship of the circumference of a circle to its diameter is pi (π ≈ 3.14) M5M2: Students will extend their.

Hannah D..  Radius is half the way across the circle  Diameter is the whole way across the circle.

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.

Warm Up Evaluate. Round to the nearest hundredth

Geometry – Circles.  Circles are shapes made up of all points in a plane that are the same distance from a point called the center.  Look at this example.

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

Circles Review 3 rd Grade Geometry. What is the diameter of a circle?

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.

+ Bell Work Solve 25 ⅚ -18 ⅜ 5 ⅛ + 7 ⅘. + Bell Work Answer 25 ⅚ -18 ⅜ 25 20/24 – 18 9/ /24 5 ⅛ + 7 ⅘ 5 5/ / /40.

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.

AREA OF A CIRCLE Learning Target 4: I can solve problems using area and circumference of a circle.

How do you find the circumference of a circle? For Example A circle has a radius of 8 centimeters. What is the circumference of the circle?

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

The midpoint of a circle is centre The line drawn from the centre to the circumference is … radius.

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

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

Opener Simplify or Solve: 1. x + 3(x – 6) 2. 4x + 5 = (3 + x)y + x² + 2xy 4. 6(x + 2) + 4x x + x – 6 = 3 6. –(x + 7) = -3.

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

PERIMETER AND AREA PRESENTATION 4 - circles and π UNIT 4 MATHS.

March 8 th,  Problem 1) A) What is the formula for the area of a circle? B) What is the formula for the circumference of a circle? C) How do these.

Geometry: Circles and Circumference

Circles: Circumference & Area

Warm Up May 14th Fill in the blanks:

Circles: Circumference & Area

Circumference and Area formulas

Spiral TAKS Review #2 6 MINUTES.

I will calculate area and perimeter of circles.

Unit 2: Ratios and Proportional Relationships

Area and Circumference

Presentation transcript:

Area of Circle

What do you get when you cross an insect with the Easter bunny? JOKE of the DAY What do you get when you cross an insect with the Easter bunny? Do Now Take your notebook and folder from your cubby. Then: Find the RADIUS, DIAMETER, CIRCUMFERENCE, and AREA of the circle to the right 5cm

Do Now Take your notebook and folder from your cubby. Then: JOKE of the DAY What do you get if you divide the circumference of a jack-o-lantern by its diameter? Do Now Take your notebook and folder from your cubby. Then: Find the RADIUS, DIAMETER, and CIRCUMFERENCE of the circle to the right 14ft

Agenda Do Now/ Hook: 5 min Notes: 10 – 15 min Explore: 15 min Guided Practice: 15 min Clean Up: 5 min 2 minutes We are a TEAM of CONFIDENT PROBLEM SOLVERS & EFFECTIVE COMMUNICATORS

Announcements HW Due Monday Quiz Tuesday/Wednesday Tutoring Sign Ups Tickets & Auction FRIDAY 2 minutes We are a TEAM of CONFIDENT PROBLEM SOLVERS & EFFECTIVE COMMUNICATORS

Parts of a Circle – Review Circumference: Perimeter of circle, distance around Formula: C = 2 * r * π Radius: Distance from the center to the edge of the circle r = d/2 Diameter: Distance across the center of the circle d = 2r Pi (π): Ratio of circumference to diameter. Always equals 3.14 Area: Space inside a figure. Formula for circles: A = π * r2

Area = Pi * Radius Squared Today’s Formula: Area = Pi * Radius Squared A = π * r2

Examples

Area Explore Trace the circular item on your graph paper With a ruler, measure the radius of the circle (from the center of the circle to the edge). Record your answer in inches in your notebook Using the A = π * r2 formula, calculate the expected area of the circle. Record your answer in inches in your notebook Look at how many square boxes make up the area of this circle. Estimate how many complete square boxes are inside the circle. Compare the expected Area from the formula with the actual measured Area from Step 3

Whiteboard Practice Show work Use markers only for the math Do not raise boards until I count to 3 Cap markers and flip boards over when we go over problems

Question 1 What is the area of this circle? A. 6 inches squared B. 28.2 inches squared C. 18.8 inches squared D. 9.4 inches squared 3in A = π * r2

Question 2 What is the area of this circle? A. 144 π inches squared B. 36 π inches squared C. 6 π inches squared D. 3 π inches squared 6in A = π * r2

Question 3 What is the area of this circle? A. 2463 feet squared B. 22 feet squared C. 44 feet squared D. 153.9 feet squared 14ft A = π * r2

Question 4 Khyren made a pizza with a diameter of 10 inches. What is the area of his pizza? 78.5 inches squared 314 inches squared 17.2 inches squared 25 inches squared A = π * r2

Question 5 Mycynthia is building a circular bird pool in her backyard. If the distance from the center of the pool to the edge is 4ft, what is the area of the pool? A. 25.1 feet squared B. 50.3 feet squared C. 16 feet squared D. 12.6 feet squared A = π * r2

Independent Practice Work independently or with your table Stay seated and raise your hand silently if you have a question When finished, work on challenge problems (on back)