Georgia 4.GSR.7.2
The Standard
Measure angles in reference to a circle with the center at the common endpoint of two rays. Determine an angle’s measure in relation to the 360 degrees in a circle through division or as a missing factor problem.
Georgia's K-12 Mathematics Standards · Investigate the concepts of angles and angle measurement to estimate and measure angles.
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students connect an angle to part of a full 360° turn around a vertex. They divide 360 by the number of equal parts or solve a missing-factor equation to find an angle.
What Mastery Looks Like
- Given a circle split into nine equal sectors, a student finds 40° using 360 ÷ 9 or 9 × 40 = 360. The student checks that all sector angles total 360°.
Common Misconceptions
- Students may divide the number of sectors by 360 or forget that the sectors must be equal. They may also confuse one sector’s angle with the total 360° turn.
How to Assess It
- Show a circle divided into 12 equal sectors and ask, “What is the measure of one central angle? Write a division equation and a multiplication check.”
Lesson moves
Ways to Teach It
Fold a paper circle into eight equal sectors, draw two radii, and calculate each central angle using 360 ÷ 8.
Ask, “A circle has six equal angles. How can division and multiplication both prove each angle is 60°?”
Play a matching game with cards showing equal circle sectors, division equations, missing-factor equations, and angle measures.
Use a clock face to find the angle between adjacent hour marks, then determine angles spanning two, three, or four marks.
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Printable 4.GSR.7.2 Worksheet
A ready-to-print activity worksheet aligned to 4.GSR.7.2, with an answer key for the teacher on its own page. No account needed.
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Related Standards
- 4.GSR.7
Investigate the concepts of angles and angle measurement to estimate and measure angles.
- 4.GSR.7.1
Recognize angles as geometric shapes formed when two rays share a common endpoint. Draw right, acute, and obtuse angles based on the relationship of the angle m...
- 7.GSR.5
Solve practical problems involving angle measurement, circles, area of circles, surface area of prisms and cylinders, and volume of cylinders and prisms compose...
- 7.GSR.5.2
Measure angles in whole number degrees using a protractor.
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