Game · Calculation
Find the missing angle
A fresh quadrilateral every round. Use the 360° rule to find x.
Three interior angles are 101°, 43° and 84°. Find the missing angle x.
Score: 0
Section 5
Activities, Practice & Learning Games
Five hands-on activities that turn the lesson into practice: compute missing angles, sort properties, answer exam-style questions, rebuild a proof, and beat the clock.
Activity 1 — The 360° Solver
Activity 2 — Property Sorting
Game · Drag & drop
Trapezium or parallelogram?
Decide whether each property belongs to the trapezium, the parallelogram, or both.
Drag each statement (or tap a card then tap a box) into the correct column.
Trapezium only
Parallelogram only
Both shapes
Activity 3 — Multiple Choice Quiz
Game · Quiz
Exam-style questions
Eight questions with instant feedback and the reason behind each answer.
Question 1 of 8Score 0
The sum of the interior angles of any quadrilateral equals:
Activity 4 — Proof Builder
Game · Reasoning
Put the proof in order
Rebuild a full geometric proof one justified statement at a time.
Prove: ABCD is a parallelogram and H lies on ray AB with AB = BH. Show that BHCD is a parallelogram. Tap the statements in the correct order.
Activity 5 — 45-Second Rush
Game · Speed
True or false rush
Fast recall of definitions and properties under time pressure.
45 seconds. How many true/false statements can you get right?
Classroom & homework tasks
Paper folding
Cut out any quadrilateral, tear off the four corners and fit them around a point. They form a full turn — 360°.
Straw parallelograms
Build a shape from two pairs of equal straws. Push it sideways: the sides stay equal and parallel, so it stays a parallelogram.
Shape hunt
Photograph five quadrilaterals around school or home — windows, tiles, railings — and classify each one with a reason.
Design challenge
Design a flowerpot face as a trapezium where m(∠C) = m(∠D). Calculate all four angles and justify the parallel sides.
Teacher tip
Ask students to state the reason for every step out loud. Naming the rule — corresponding, alternate, co-interior, vertically opposite — is what earns full marks in proof questions.