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Fourth Grade Math Curriculum

Measuring and Drawing Angles

Table of Contents

Topic Pages Days

Measuring and Drawing Angles Teacher Notes

MATH_4_A_1 MEASURING AND DRAWING ANGLES 2014_LES

Part I – Angles, Degrees, and Fractional Parts of a Circle

Part II – Pearson Video/Measuring and Drawing Angles

Part III – Practice Pages/Measuring and Drawing Angles

Part IV – Classifying Angles in Relation to Degrees

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Part I SmartBoard MATH_4_A_2 ANGLES DEGREES AND FRACTIONAL PARTS OF A CIRCLE SMARTBOARD 2014_RES

2 DAYS

IMN Record Sheet MATH_4_A_3 ANGLES AND DEGREES IMN 2014_RES

Angles Student Booklet MATH_4_A_4 ANGLES STUDENT BOOKLET 2014_RES

Pearson Video MATH_4_A_5 PEARSON VIDEO 2014_RES

QR Code Activity MATH_4_A_6 ANGLES QR CODE ACTIVITY 2014_RES 1 DAY

Independent Practice MATH_4_A_7 GEOMETRY INDEPENDENT PRACTICE 2014_RES

1 DAY

Additional Resource:

Angle Student Booklet Answer Key (pages 1-3) – MATH_4_A_4 ANGLES STUDENT BOOKLET ANSWER KEY 2014_RES

Measuring and Drawing AnglesProperty of Cy-Fair ISD Math Department (4th Grade) 2014-2015 0

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4.7 A – (Not tested) – illustrate the measure of an angle as the part of a circle whose center is at the vertex of the angle that is “cut out” by the rays of the angle. Angle measures are limited to whole numbers.4.7 B – (Not tested) – illustrate degrees as the units used to measure an angle, where 1/360 of any circle is one degree and an angle that “cuts” n/360 out of any circle whose center is at the angle’s vertex has a measure of n degrees. Angle measures are limited to whole numbers. 4.7 C – Readiness – determine the approximate measure of angles in degrees to the nearest whole number using a protractor.4.7 D – Supporting – draw an angle with a given measure.Materials: Protractors, Part I SmartBoard (MATH_4_A_2 ANGLES DEGREES AND FRACTIONAL PARTS OF A CIRCLE SMARTBOARD 2014_RES), Angles and Degrees IMN Record Sheet (MATH_4_A_3 ANGLES AND DEGREES IMN 2014_RES), Angles Student Booklet (MATH_4_A_4 ANGLES STUDENT BOOKLET 2014_RES), Pearson video (MATH_4_A_5 PEARSON VIDEO 2014_RES)Part I: Angles, Degrees and Fractional Parts of a Circle (TEKS 4.7A and 4.7B)Teacher note: This is a teacher demo only.

This quick demo is a series of 5 slides that take the students through the making of an angle and how it relates to a circle. This illustration proves that an angle is constructed by two rays and a vertex, and angles can be drawn around a point to create a circle.Project the SmartBoard slides and discuss with students for understanding.

Slide 2:

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Allow students to ponder on the question on this beginning slide.

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Slide 3:

Slide 4:

Slide 5:

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Here you are getting the students to see that a sum of angles can form a circle.If we have an angle measuring 1 degree, how many 1 degree angles will it take to form a complete circle?

This is a visual of a complete circle showing 360 total degrees broken into 10 degree measurements.It answers the question from Slide 2. (It would take 360 one degree angles to complete a circle).

To take it a step further, increase the 1 degree angle to a right angle. At this time, the students are unaware that a right angle measures 90 degrees.

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Which unit fraction is represented on the circle? (One-fourth)What is formed by the shaded unit fraction? (An angle)What components are necessary to form an angle? (Two rays and a vertex)Can we determine the type of angle without using a protractor? Why? (Yes, because it forms a square corner or a right angle) What type of lines are used to form a right angle? (Perpendicular lines)To determine the measure of a right angle, what tool should we use? (A protractor)Show students that a right angle measures to 90 degrees using a protractor.

What angle is represented by the shaded portion of the circle? (90 degrees)So, a right angle always measures how many degrees? (90)Slide 6:

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The bottom section of this slide is covered by a shade.

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So the shaded angle cuts out one-fourth or one quarter of the circle. How many 90 degree angles would complete a full circle? (4) Why? (The circle is cut into 4 equal parts and each part is equal to 90 degrees)Can we determine the total degrees of a circle if we know what one-fourth of the circle measures? (Yes) How? (We know that one 90 degree angle is one-fourth of the circle; therefore, two-fourths of the circle would equal two 90 degree angles or 180 degrees) So half a circle is 180 degrees, which also represents a straight line. Therefore, how would we calculate the degrees of a full circle? (90 x 4 or 180 x 2)A circle has how many total degrees? (360 degrees)Part II: Pearson Video - Measuring and Drawing AnglesStudents will use the Angle Student Booklet while watching the Pearson video on measuring and drawing angles.

Part III: Practice Pages – Measuring and Drawing AnglesProperty of Cy-Fair ISD Math Department (4th Grade) 2014-2015 4

Use the video recording included in the resource folder.MATH_4_A_PEARSON VIDEO 2014_RES.wmv

These are the first 3 pages of the booklet. Students will fill in the blanks as they view the video. The answers for these 3 pages are in a separate document (see Table of Contents).

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Part IV: Classifying Angles in Relation to DegreesAs an introductory activity have the students pull off page 6 in their Angles Student Booklet. They will need to cut the angles apart and sort them based on the sticky note strategy. Once sorted, have students measure with a protractor and have discussion based on the measurements why they are sorted either under right, acute, or obtuse.

On the “Protractor Practice” and the IMN page it may be helpful for students to extend the ray of the angle out so that a clear measurement can be taken from the protractor.

Students will need the “Angles and Degrees IMN Record Sheet” when discussing angles and degrees. Students can fold and glue the back side in their IMN. Discuss with students that angles can be classified as right, obtuse, acute, and straight not only in relation to the corner of a STAAR Mathematics Chart, but also based on the measure of the angle. Have students complete their IMN with the following information.

Protractor – a tool used to measure and draw angles.Degree – units used to measure an angle.

Right Angle – exactly 90

Obtuse Angle – greater than 90 and less than 180

Acute Angle – less than 90

Straight Angle – exactly 180

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These last 3 pages of the booklet can be used as additional practice on using the protractor.

Protractor PracticeThis worksheet will be used just before the IMN, to introduce angles and how they relate to degrees.

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ABC = 90

JKL = 165

S = 26

PQR = 180

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NOTE: The IMN is inclusive of the multiple ways to name an angle. For example, the obtuse angle drawing is LKJ, whereas the fill in the blank for the measurement states

JKL. Likewise, the acute angle drawing is RST, and the fill in the blank for the

measurement states S.