Stage 9 - Q1 - 2 marks
Find angle \(ABC\). Use the exterior angle and give a reason.
Hint
Combine the straight-line and triangle-angle sums.
Stage 9 - Q2 - 2 marks
\(AB=AC\). Find the two base angles.
Hint
Subtract the vertex angle, then divide by two.
Stage 9 - Q3 - 3 marks
\(AB\) is parallel to \(CD\). Find angles PQD and CQP.
Hint
Use the parallel lines first, then the straight line.
Stage 9 - Q4 - 3 marks
ABCD is a parallelogram. Find angles \(ABC\) and ACB.
Hint
The diagonal splits the corner at A.
Stage 9 - Q5 - 4 marks
\(AB=AC=AD\). Find angles \(BAD\) and \(BCD\).
Hint
\(AC\) is an equal side in both triangles.
Stage 9 - Q6 - 4 marks
\(AB=AC=AD\). Find angles \(BAD\) and \(BCD\).
Hint
\(AC\) is an equal side in both triangles.
Stage 9 - Q7 - 5 marks
The four corner angles follow this pattern. Find \(x\) and the largest angle.
Hint
Add all four angle expressions.
Stage 9 - Q8 - 5 marks
O is the centre; \(AC\) is a diameter. Find angles OAB, OCB and \(ABC\) using equal radii.
Hint
Find both isosceles base angles before combining them.
Stage 9 - Q9 - 5 marks
ABCD is a parallelogram. Find \(x\), angle DAB and angle \(ABC\).
Hint
Use the adjacent-angle relationship to construct an equation.
Stage 9 - Q10 - 3 marks
\(AB=AC=AD\). The given angles are algebraic and angle \(BAD\) is \(132^\circ\). Find \(x\) and angle \(BCD\).
Hint
The angles at C match the base angles at B and D.