Starter The perimeter of this sector is (2r + 12∏) m. Find the radius r m, of the sector. r m.

Slides:

Advertisements

Similar presentations

L.O. Students will be able to calculate the area of a sector of a circle, by working in small groups and completing an investigation. Standards: 6.G.8.

Advertisements

Arcs & Sectors Basic Definitions Calculating Arc Length Unit Assessment Level Questions Calculating Sector Area Course level questions.

Radians In a circle of radius 1 unit, the angle  subtended at the centre of the circle by the arc of length 1 unit is called 1 radian, written as 1 rad.

Targeting Grade C SSM 3 Circles GCSE Mathematics.

Mathematics Circles.

  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.

C2: Arcs, Sectors and Segments

7.7: Areas of Circles and Sectors

Parallel-ograms & Trapezoids Rectangles & Triangles Regular Polygons

Circle Properties An Arc is a fraction of the circumference A sector is a fraction of a circle. Two radii and an arc A B O 3 cm r = 3 cm d = 6 cm Arc AB.

Radian Measure. Many things can be measured using different units.

Radians, Arc Length and Sector Area 40: Radians, Arc Length and Sector Area.

8cm Q1 Arcs, Sectors and Segments

Circles - A reminder.

GCSE: Circles Dr J Frost Last modified: 6 th October 2013.

Warm up: Solve for x 18 ◦ 1.) x 124 ◦ 70 ◦ x 2.) 3.) x 260 ◦ 20 ◦ 110 ◦ x 4.)

Warm up: Solve for x 1.) 2.) 4.) 3.) 124◦ 70◦ x 18◦ x 260◦ x 20◦ 110◦

11.4 Circumference and Arc Length

Note 2: Perimeter The perimeter is the distance around the outside of a shape. Start at one corner and work around the shape calculating any missing sides.

Year 9 Arcs and Sectors Dr J Frost Last modified: 5 th May 2015 Objectives: Be able to calculate the area of a sector,

Warm-up Find the circumference and area of the following circles: R = 7 ft D = 20 in.

Calculating sector areas and arc lengths. Look at these relationships. What do you notice? Radius = R π R/2 R π 3 π R/2 2 π R Degrees Circumference.

Area of a Sector and Length of an arc Ms N. Kearney.

Arc Length and Sector Area. How do we get the fraction in these formulas? How many degrees are in a circle? Fraction = (central angle/360)

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

Radians, Arc Length and Sector Area. Radians Radians are units for measuring angles. They can be used instead of degrees. r O 1 radian is the size of.

RADIANS Radians, like degrees, are a way of measuring angles.

Geometry Warm Up CIRCLES AND ARCS Objective: To find the circumference and arc length.

10.9 Circumference and Arc Length After studying this section, you will be able to determine the circumference of a circle and the length of an arc.

Angular measurement Objectives Be able to define the radian. Be able to convert angles from degrees into radians and vice versa.

Circles: Arc Length and Sector Area

Circles…… Area and Circumference The Circumference of a Circle Find the circumference of the following circles. C =  d C = 2  r 8 cm cm 2 C =

A.2 B.3 C.4 D.5 Refer to the figure. Find BC.. A.2 B.3 C.4 D.5 Refer to the figure. Find BC.

Warm up: Solve for x 18 ◦ 1.) x 124 ◦ 70 ◦ x 2.) 3.) x 260 ◦ 20 ◦ 110 ◦ x 4.)

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

Starter Find the Perimeter and Area of this shape… 12m 15m Perimeter 15m + 15m + 12m = 42m C = πd C = π x 12 C = 37.70m (2dp) Semi circle so… ÷

O A B AOB = Sector / Juring = Arc / Busur ARC SECTOR Arc lengths and Areas of Sectors Created by ﺠﻴﻄ for Mathlabsky.wordpress.com.

11.4 – Circumference and Arc Length. Circumference: C =  dC = 2  r Length around a circle.

Sector of a Circle Section  If a circle has a radius of 2 inches, then what is its circumference?  What is the length of the arc 172 o around.

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

Trigonometry Section 7.2 Calculate arclengths and areas of a sectors Note: The arclength and the area of the sector are a fraction of the circumference.

Perimeter and Area with Circles. Circumference of a Circle Circumference is the perimeter of the circle Formula: or (for exact answers, leave π in your.

CIRCLES RADIUS DIAMETER (CHORD) CIRCUMFERENCE ARC CHORD.

Sections Perimeter and Area with Circles.

It’s the same for all circles! The Circumference of a Circle.

AGENDA KAHOOT REVIEW LESSON 81 WORK TIME. LESSON 81: CENTRAL ANGLES AND ARCS Central Angle: an angle whose vertex is the center of the circle.

8th Grade Math Chapter 9a Review

Solve Problems Involving the Circumference and Area of Circles

Arcs, Sectors & Segments

11.3 Areas of Circles and Sectors

11.3 Sector Area and Arc Length (Part 1)

Questions over hw?.

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

9-2 and 11-3: Perimeter and Area of Circles and Sectors

11.1 Vocabulary Circumference PI () Arc Length Radian.

14 inch 7 inch Which one contains more calories? a)They both contain the same amount b)Half the 14 inch pizza has more c)The full 7 inch pizza contains.

Revision: Circles Silent Intelligent Practice Teacher Your Turn

Questions over hw?.

Questions over hw?.

Warm Up #1 Find each measure. Give answers in terms of  and rounded to the nearest hundredth. 1. area of sector LQM 7.5 in2  in2.

Calculate Areas of Sectors

Objectives Find arc lengths..

Starter Questions S3 Q1. Calculate

On your whiteboards The radius of this circle is 30 cm What is the circumference of this circle in terms of pi? Show your calculation. Compare and.

Sector Area and Arc Length

EOCT REVIEW #2 Circles – Angles, Arcs, Area of a Circle, Area of a Sector, Circumference, Arc Length, & Segments.

11.1 Vocabulary Circumference PI () Arc Length Radian.

Starter Calculate the area and circumference (or perimeter) of the following shapes. Give your answers correct to 3 significant figures. A = 38.5 cm² C.

Starter Which of these shapes has the greatest perimeter?

Presentation transcript:

Starter The perimeter of this sector is (2r + 12∏) m. Find the radius r m, of the sector. r m

Arcs and Sectors Learning Objectives: Able to solve problems in terms of pi Able to calculate the arc length Able to calculate the area of a sector 11/09/2012Grade A/A*

Arc Length 30 o What fraction of the circle is shown by this sector? To calculate the length of an arc or area of a sector, we need to know this.

Arc Length An arc is a fraction of the circumference We get this fraction from the angle at the centre

Arc Length r

30 o 18cm

Area of a Sector r

Area of sector 30 o 18cm

Arcs and Sectors Calculate the length of the arc and the area of the sector 70 o 11m

Starter Find the length of the arc and area of the sector Find the radius of this sector.

Arcs and Sectors Learning Objectives: Able to calculate the arc length Able to calculate the area of a sector Able to find the radius, given the arc length or area of a sector 11/09/2012Grade A/A*

Arcs and Sectors Find the radius of this sector. Give your answer to 1dp. (÷ ∏) (√)

Arcs and Sectors Calculate the angle at the centre of this sector. Give your answer to 1dp. (x 360)

Arcs and Sectors Calculate the angle at the centre of this sector. Give your answer to 1dp. (x 360) 125cm 2 9cm

Starter 27 o 256m 2 Calculate the length of the arc of the major sector.

Starter 27 o 256m 2 (÷ ∏) (√)

Starter 27 o 256m …m

145 o 9cm

16 o 14m 175cm 2 r 13cm