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GR.12.3

Problem solving - angles in triangles and quadrilaterals

Solve angle problems in triangles and quadrilaterals

3 hand-picked video lessons for this topic, each checked for relevance and clarity, graded by difficulty and labelled by depth. Press play to watch — nothing loads from YouTube until you do.

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Grade 3–6 Core 🇬🇧 UK

Angles in Triangles and Quadrilaterals | Grade 5 Crossover | GCSE Maths Tutor

The GCSE Maths Tutor 48K views

Full GCSE walkthrough of finding missing angles in triangles, quadrilaterals and combined shapes.

Jump to 0:34Angles in Triangles 5:53Practice Questions 9:09Angles in Quadrilaterals 10:54Practice Questions 12:55Combining Shapes 16:04Practice Question

Grade 2–5 Core 🇬🇧 UK

Angles in a Quadrilateral

corbettmaths 328K views

Corbett explains finding missing angles in quadrilaterals including kites, trapezia and parallelograms.

Grade 2–5 Core 🇬🇧 UK

GCSE Maths - 5 Angle Rules to Know (2026/27 exams)

Cognito 258K views

Five essential angle rules for triangles and quadrilaterals, ending with a complex problem.

Jump to 0:14Rule 1: Angles in a Triangle 2:02Rule 3: Angles in a Quadrilateral 3:09Rule 5: Isosceles Triangles 5:18Complex Problem Example