Area of a Triangle Using ½ab sin C | Step-by-Step

Learn how to find the area of any triangle using the formula ½ab sin C — step-by-step. This works on any triangle, not just right-angled ones, so it's perfect for when you can't use half base times height. Area = ½ ab sin C The one rule to remember: the angle C must be the included angle — the angle sitting between the two sides a and b. If the angle isn't between your two chosen sides, the formula won't work. In this video we work through a straightforward area, a question where you have to pick the right angle from a cluttered diagram, and a harder example where you're given the area and have to work backwards to find a missing side. Perfect for Year 10 and Year 11 students learning trigonometry, anyone revising for a maths exam, or learners who need a clear walkthrough with no skipped steps. 📘 What you'll learn: The formula for the area of any triangle: ½ ab sin C Why the angle must be the included angle (between the two sides) How to find the area when given two sides and the angle between them How to pick the right angle when a diagram has extra measurements How to work backwards — finding a missing side when given the area Remembering to put your calculator in degrees mode ⏱️ Timestamps: 00:00 The formula & the included angle rule 02:08 Example 1 — finding the area 04:13 Example 2 — picking the right angle 06:02 Example 3 — working backwards to find a side 🎯 Who this is for: Year 10 and Year 11 Higher tier students, GCSE and IGCSE students revising for exams, learners who know the sine and cosine rules and want the area formula, and anyone who wants a clear tutorial that shows every step. 📚 Part of my trigonometry series: The Sine Rule    • How to Use the Sine Rule in Non-Right-Angl...   The Cosine Rule    • How to Use the Cosine Rule in Non-Right-An...   🔗 Find more maths lessons and tutoring resources: https://tutor-marketplace.com If this video helped, please like and subscribe for more step-by-step maths tutorials. #AreaOfATriangle #Trigonometry #Trig #NonRightAngledTriangles #Year10Maths #Year11Maths #MathsTutorial #GCSEMaths #MathHelp #Mathematics