Give reasons / Give a reason
In angle and circle questions, name the theorem or rule that justifies your step.
Definition
When asked to give reasons, you must name the specific angle rule (e.g. "angles on a straight line sum to 180°", "alternate angles are equal", "angle at the centre is twice angle at the circumference"). Vague answers like "geometry" earn zero.
Example
Find x and give a reason. "x = 60° because angles in a triangle sum to 180°."
Common confusion
Saying "from the diagram" or "it is obvious" earns nothing. Name the rule.
Used in these topics
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