Angles
Cambridge IGCSE Mathematics (0580) · Unit 4: Geometry · 10 flashcards
Angles is topic 4.1 in the Cambridge IGCSE Mathematics (0580) syllabus , positioned in Unit 4 — Geometry , alongside Angles in polygons, Parallel lines and Triangles. In one line: An acute angle is an angle that measures greater than 0° and less than 90°.
This topic is examined across Paper 1 (Core) or Paper 2 (Extended) — non-calculator — and Paper 3 (Core) or Paper 4 (Extended) — calculator.
The deck below contains 10 flashcards — 6 definitions and 1 key concept — covering the precise wording mark schemes reward. Use the 6 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.
An acute angle and provide an example
An acute angle is an angle that measures greater than 0° and less than 90°.
Questions this Angles deck will help you answer
- › Explain the property of vertically opposite angles with a diagrammatic example.
Define an acute angle and provide an example.
An acute angle is an angle that measures greater than 0° and less than 90°.
What is an obtuse angle? Give an example.
An obtuse angle is an angle that measures greater than 90° and less than 180°. An example of an obtuse angle is 120°.
What is a reflex angle? How does it differ from an obtuse angle?
A reflex angle is an angle that measures greater than 180° and less than 360°. An obtuse angle is less than 180°, while a reflex angle is greater than 180°.
Two angles form a straight line. One angle is 60°. What is the measure of the other angle?
Angles on a straight line add up to 180°. Therefore, the other angle is 180° - 60° = 120°.
Define 'complementary angles'. Give an example.
Complementary angles are two angles that add up to 90°.
What are 'supplementary angles'? Illustrate with an example.
Supplementary angles are two angles that add up to 180°.
Three angles meet at a point. Their measures are 100°, 150°, and x. Find the value of x.
Angles at a point add up to 360°. Therefore, 100° + 150° + x = 360°. Solving for x gives x = 360° - 250° = 110°.
Explain the property of vertically opposite angles with a diagrammatic example.
Vertically opposite angles are the angles opposite each other when two lines intersect. Vertically opposite angles are equal. For instance, if two lines cross, and one angle is 40°, the angle directly opposite is also 40°.
What is a full turn in terms of degrees?
A full turn is equal to 360 degrees. This represents a complete rotation around a point.
If angle A and angle B are complementary, and angle A is 25 degrees, find the measure of angle B.
Since complementary angles add up to 90 degrees, angle B = 90 - angle A = 90 - 25 = 65 degrees.
Key Questions: Angles
Define an acute angle and provide an example.
An acute angle is an angle that measures greater than 0° and less than 90°.
What is an obtuse angle? Give an example.
An obtuse angle is an angle that measures greater than 90° and less than 180°. An example of an obtuse angle is 120°.
What is a reflex angle? How does it differ from an obtuse angle?
A reflex angle is an angle that measures greater than 180° and less than 360°. An obtuse angle is less than 180°, while a reflex angle is greater than 180°.
Define 'complementary angles'. Give an example.
Complementary angles are two angles that add up to 90°.
What are 'supplementary angles'? Illustrate with an example.
Supplementary angles are two angles that add up to 180°.
Tips to avoid common mistakes in Angles
- ● When finding trig solutions, consider the unit circle and ensure your graph covers all possible values you might need.
- ● Refresh your memory on all the circle angle theorems, visualizing each one with example diagrams.
- ● When finding angles (Q21), carry as many decimal places as possible through each stage, only rounding the angle at the very end.
- ● Memorize the formula: number of sides in a regular polygon equals 360 divided by the measure of one exterior angle, and rearrange to isolate 'n'.
More topics in Unit 4 — Geometry
Angles sits alongside these Mathematics decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.
9 flashcards
10 flashcards
10 flashcards
9 flashcards
9 flashcards
9 flashcards
9 flashcards
9 flashcards
9 flashcards
Cambridge syllabus keywords to use in your answers
These are the official Cambridge 0580 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.
Key terms covered in this Angles deck
Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.
Related Mathematics guides
Long-read articles that go beyond the deck — cover the whole subject's common mistakes, high-yield content and revision pacing.
How to study this Angles deck
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