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Free Grade 3 Vertically Opposite Angles in Context Flashcards

Free Grade 3 flashcards for Vertically Opposite Angles 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°.

Price

Free

Difficulty

Foundation

Estimated time

20 min

Total marks

24

Learning objectives

Every objective is checkable, and each one maps to an activity and an assessment.

  • UnderstandExplain vertically opposite angles in context

    Explain vertically opposite angles in context accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • ApplyCalculate vertically opposite angles in context

    Calculate vertically opposite angles in context accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • AnalyseCompare vertically opposite angles in context

    Compare vertically opposite angles in context accurately in a familiar context.

    Assessed by: Exit ticket of four short items

  • EvaluateJustify vertically opposite angles in context

    Justify vertically opposite angles 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 Vertically Opposite Angles 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°.

Key wordsdegreeacuteobtusereflexinterior angle

12 practice questions

Easy to hard, 24 marks in total. Try them first, then open the answers.

  1. 1.Two angles on a straight line. One is 116°. Find the other.[1]
  2. 2.Two angles on a straight line. One is 153°. Find the other.[1]
  3. 3.Two angles on a straight line. One is 79°. Find the other.[1]
  4. 4.Two angles on a straight line. One is 136°. Find the other.[1]
  5. 5.A triangle has angles 68° and 69°. Find the third angle.[2]
  6. 6.A triangle has angles 56° and 23°. Find the third angle.[2]
  7. 7.A triangle has angles 66° and 64°. Find the third angle.[2]
  8. 8.A triangle has angles 37° and 36°. Find the third angle.[2]
  9. 9.Find the size of each interior angle of a regular 7-sided polygon.[3]
  10. 10.Find the size of each interior angle of a regular 5-sided polygon.[3]
  11. 11.Find the size of each interior angle of a regular 9-sided polygon.[3]
  12. 12.Find the size of each interior angle of a regular 10-sided polygon.[3]
Show answers and working
  1. 1. 64°

    Angles on a straight line add to 180°. 180 − 116 = 64°.

  2. 2. 27°

    Angles on a straight line add to 180°. 180 − 153 = 27°.

  3. 3. 101°

    Angles on a straight line add to 180°. 180 − 79 = 101°.

  4. 4. 44°

    Angles on a straight line add to 180°. 180 − 136 = 44°.

  5. 5. 43°

    Angles in a triangle add to 180°. 180 − 68 − 69 = 43°.

  6. 6. 101°

    Angles in a triangle add to 180°. 180 − 56 − 23 = 101°.

  7. 7. 50°

    Angles in a triangle add to 180°. 180 − 66 − 64 = 50°.

  8. 8. 107°

    Angles in a triangle add to 180°. 180 − 37 − 36 = 107°.

  9. 9. 128.57°

    Sum of interior angles = (7 − 2) × 180 = 900°. Each angle = 900 ÷ 7 = 128.57°.

  10. 10. 108°

    Sum of interior angles = (5 − 2) × 180 = 540°. Each angle = 540 ÷ 5 = 108°.

  11. 11. 140°

    Sum of interior angles = (9 − 2) × 180 = 1260°. Each angle = 1260 ÷ 9 = 140°.

  12. 12. 144°

    Sum of interior angles = (10 − 2) × 180 = 1440°. Each angle = 1440 ÷ 10 = 144°.

Worked examples

Easy example

Two angles on a straight line. One is 59°. Find the other.

  1. Angles on a straight line add to 180°.
  2. 180 − 59 = 121°.
  3. Answer: 121°
Medium example

A triangle has angles 64° and 21°. Find the third angle.

  1. Angles in a triangle add to 180°.
  2. 180 − 64 − 21 = 95°.
  3. Answer: 95°
Hard example

Find the size of each interior angle of a regular 6-sided polygon.

  1. Sum of interior angles = (6 − 2) × 180 = 720°.
  2. Each angle = 720 ÷ 6 = 120°.
  3. Answer: 120°

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.

NATIONAL-CURRICULUM NAT-223.1 — Mapped statement covering Vertically Opposite Angles in Context.IB IB-864.2 — Mapped statement covering Vertically Opposite Angles in Context.

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Frequently asked

Is this Grade 3 Vertically Opposite Angles in Context flashcards really free?
Yes. Every flashcards 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 Vertically Opposite Angles, Introducing Vertically Opposite Angles, Angles Around a Point. Each one has its own free lesson, worksheet and quiz.
How is the flashcards 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 Vertically Opposite Angles in Context?
Move on to Angles on a Straight Line, Angles Around a Point, Angles in Parallel Lines, Angles in Polygons, which build directly on this idea.

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