Free Grade 3 Angle Bisector in Context Worksheets
Free Grade 3 worksheets for Angle Bisector in Context: 12 real questions with a full answer key and worked solutions. Angles on a straight line add to 180°, around a point to 360°, and inside a triangle to 180°. A polygon with n sides has interior angles adding to (n − 2) × 180°.
Free
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35 min
24
Learning objectives
Every objective is checkable, and each one maps to an activity and an assessment.
- UnderstandExplain angle bisector in context
Explain angle bisector in context accurately in a familiar context.
Assessed by: Exit ticket of four short items
- ApplyCalculate angle bisector in context
Calculate angle bisector in context accurately in a familiar context.
Assessed by: Exit ticket of four short items
- AnalyseCompare angle bisector in context
Compare angle bisector in context accurately in a familiar context.
Assessed by: Exit ticket of four short items
- EvaluateJustify angle bisector in context
Justify angle bisector in context accurately in a familiar context.
Assessed by: Exit ticket of four short items
Prerequisites
Close these gaps first — each has its own free lesson, worksheet and quiz.
How Angle Bisector in Context works
Angles on a straight line add to 180°, around a point to 360°, and inside a triangle to 180°. A polygon with n sides has interior angles adding to (n − 2) × 180°.
12 practice questions
Easy to hard, 24 marks in total. Try them first, then open the answers.
- 1.Two angles on a straight line. One is 120°. Find the other.[1]
- 2.Two angles on a straight line. One is 148°. Find the other.[1]
- 3.Two angles on a straight line. One is 132°. Find the other.[1]
- 4.Two angles on a straight line. One is 94°. Find the other.[1]
- 5.A triangle has angles 58° and 49°. Find the third angle.[2]
- 6.A triangle has angles 79° and 24°. Find the third angle.[2]
- 7.A triangle has angles 88° and 70°. Find the third angle.[2]
- 8.A triangle has angles 36° and 73°. Find the third angle.[2]
- 9.Find the size of each interior angle of a regular 6-sided polygon.[3]
- 10.Find the size of each interior angle of a regular 7-sided polygon.[3]
- 11.Find the size of each interior angle of a regular 10-sided polygon.[3]
- 12.Find the size of each interior angle of a regular 6-sided polygon.[3]
Show answers and working
1. 60°
Angles on a straight line add to 180°. 180 − 120 = 60°.
2. 32°
Angles on a straight line add to 180°. 180 − 148 = 32°.
3. 48°
Angles on a straight line add to 180°. 180 − 132 = 48°.
4. 86°
Angles on a straight line add to 180°. 180 − 94 = 86°.
5. 73°
Angles in a triangle add to 180°. 180 − 58 − 49 = 73°.
6. 77°
Angles in a triangle add to 180°. 180 − 79 − 24 = 77°.
7. 22°
Angles in a triangle add to 180°. 180 − 88 − 70 = 22°.
8. 71°
Angles in a triangle add to 180°. 180 − 36 − 73 = 71°.
9. 120°
Sum of interior angles = (6 − 2) × 180 = 720°. Each angle = 720 ÷ 6 = 120°.
10. 128.57°
Sum of interior angles = (7 − 2) × 180 = 900°. Each angle = 900 ÷ 7 = 128.57°.
11. 144°
Sum of interior angles = (10 − 2) × 180 = 1440°. Each angle = 1440 ÷ 10 = 144°.
12. 120°
Sum of interior angles = (6 − 2) × 180 = 720°. Each angle = 720 ÷ 6 = 120°.
Worked examples
Two angles on a straight line. One is 158°. Find the other.
- Angles on a straight line add to 180°.
- 180 − 158 = 22°.
- Answer: 22°
A triangle has angles 33° and 120°. Find the third angle.
- Angles in a triangle add to 180°.
- 180 − 33 − 120 = 27°.
- Answer: 27°
Find the size of each interior angle of a regular 5-sided polygon.
- Sum of interior angles = (5 − 2) × 180 = 540°.
- Each angle = 540 ÷ 5 = 108°.
- Answer: 108°
Interactive practice
Free, no account required — answer on screen or print it.
Common mistakes
What learners typically get wrong, and how to fix it.
Reads the wrong scale on a protractor.
Correction: Start from the 0 on the arm you are measuring from.
Uses 360° for a triangle.
Correction: Triangle = 180°, quadrilateral = 360°.
Teacher tips
- · Estimate the angle type before measuring.
Parent tips
- · Spot right angles around the house.
Real-life applications
- · Ramps, clock hands, building and design.
Assessment objectives
How mastery is evidenced, and which standards it maps to.
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Frequently asked
- Is this Grade 3 Angle Bisector in Context worksheet really free?
- Yes. Every worksheets on FreeMathWorksheet is free to use, print and share — no account, no paywall and no watermark.
- What should a learner already know before this?
- Start with Working with Angle Bisector, Introducing Angle Bisector, Perpendicular Bisector. Each one has its own free lesson, worksheet and quiz.
- How is the worksheet sequenced?
- Recognition first, then understanding, application, reasoning and finally mastery — the same ladder used across every free resource on the platform.
- What comes next after Angle Bisector in Context?
- Move on to Perpendicular Bisector, Loci, which build directly on this idea.
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