Understanding that angles in a quadrilateral add up to 360° and using this to find missing angles.
Where your child meets this in real life: Understanding angles in picture frames, tiles, or building plans
Each SEAG paper has 28 maths questions. Questions 29 to 50 are multiple choice with five possible answers, and questions 51 to 56 need a short written answer. With 56 questions in 60 minutes across English and maths, that is about a minute per question.
SEAGReady breaks angles in quadrilaterals into 3 steps, taught in order so each skill builds on the last.
Find a missing angle in a quadrilateral when three angles are given
Find missing angles when some angles are right angles or described as equal
Find missing angles using properties of rectangles, parallelograms, and other special quadrilaterals
Try three free questions from our angles in quadrilaterals course. They start easy and get harder, so you can see where your child's confidence runs out. If they manage the last one without a hint, this topic is probably secure. If not, the steps above show where to start.
The quadrilateral shown has angles of 80°, 95°, 110°, and one unknown angle. What is the missing angle?
The quadrilateral shown has one right angle and two other angles of 85° and 95°. What is the fourth angle?
A parallelogram has one angle that is three times as large as the adjacent angle. What are all four angles?
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
James is designing a kite for the school fair. The four corners of the kite have angles of 85 degrees, 90 degrees, 105 degrees, and one unknown angle.
What is the missing angle?
85° + 90° + 105° + x° = 360°
Write down the three known angles: 85°, 90°, 105°
Step 1 of 4
James is designing a kite for the school fair. The four corners of the kite have angles of 85 degrees, 90 degrees, 105 degrees, and one unknown angle.
What is the missing angle?
The missing angle of the kite is 80°.
The key insight: All four angles in ANY quadrilateral always add up to 360 degrees!
Common mix-up: Using 180° instead of 360°. 180° is for triangles. Quadrilaterals have four angles that sum to 360°.
These are the misconceptions we see most often in angles in quadrilaterals, including the ones our practice questions are specifically designed to catch.
Struggling with angles in quadrilaterals? The real gap is often in one of these earlier topics.
Sitting the SEAG test this November? Read our last-month revision plan, Paper 1 vs Paper 2 and test day guide.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.
Free to start · no card needed