Finding Missing Angles
Maths: Year 5 & 6 National Curriculum, topic 3.3.3
Angles on a Straight Line
Angles on a straight line always add up to 180°.
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Angles on a straight line
- The angle created by a straight line is always 180°.
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Find the missing angle a
- The straight line is an angle of 180° in total.
- You have a line that creates an angle of 30°.
- You can find the size of angle a by working out 180° − 30°.
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Angle a = 150°
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Example 2
Angles in a Circle
Angles in a circle always add up to 360°.
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Angles in a circle
- The angles in a circle always add up to 360°.
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Find the missing angle c
- The angles in a circle always add up to 360°.
- You can find angle c by working out 360° − 240°.
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Angle c = 120°
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Example 2
Test yourself on Finding Missing Angles
What do angles on a straight line always add up to?
What do the angles in a circle always add up to?