Question P5–P6 Angle chasing
Today’s problem — free all day, every step. Every day has one.
In triangle PQR, angle P = 48 degrees and angle Q is twice angle R. Find the size of angle R.
Answer
angle R = 44° (and angle Q = 88°).
One angle gives you the next, until you reach the angle asked for.
In this one. The angle sum turns the two unknowns into one known total (132°), and the words "twice as big" split that total into 3 equal units — 2 for Q, 1 for R.
A figure has several angles marked with only one or two values given, and words like 'isosceles', 'parallel', or 'straight line' point to which rule to use first.
Children apply an angle rule to the wrong triangle or the wrong straight line in a crowded figure, or stop one step before the angle actually asked for.
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