Foundation Mathematics Primary 6 Geometry

A geometric jewellery pendant is shaped like the parallelogram ABCD. The angle at vertex A, ∠DAB, measures 70°. What is the size of ∠BCD, the angle at vertex C (the vertex OPPOSITE to A)?

A 20°
B 70°
C 110°
D 290°
Show Worked Solution

Worked Solution

Step 1: Recall the property. In a parallelogram, OPPOSITE angles are equal. ∠A = ∠C and ∠B = ∠D. Step 2: ∠DAB and ∠BCD are at opposite vertices (A and C), so they are opposite angles. ∠BCD = ∠DAB = 70°. Check: consecutive angles add to 180°, so ∠B = 180° − 70° = 110°, and ∠D = 110°. Total = 70° + 110° + 70° + 110° = 360° ✓. Final answer: ∠BCD = 70°. Answer: 70°

Correct answer: 70°

Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.

Start Free Trial — 7 Days Free