Pythagoras' Theorem (Finding Hypotenuse)
Use a² + b² = c² to find the longest side (hypotenuse) in right-angled triangles.
Complete GCSE coverage from basic Pythagoras to advanced trigonometry including sine rule, cosine rule, and 3D applications.
Right-angled triangles, 3D applications, sine/cosine rules.
Approximate guided learning.
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Start with Chapter 9.1 to begin this section.
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Use a² + b² = c² to find the longest side (hypotenuse) in right-angled triangles.
Rearrange Pythagoras to find one of the shorter sides when given the hypotenuse.
Apply Pythagoras to real-world contexts: ladders, diagonals, distances, and more.
Find lengths in 3D shapes: cuboids, pyramids, and complex structures.
Learn the fundamental trigonometric ratios: sine, cosine, and tangent.
Use sin, cos, and tan to calculate unknown sides in right-angled triangles.
Use inverse trig functions (sin⁻¹, cos⁻¹, tan⁻¹) to find unknown angles.
Apply trigonometry to real-world problems: angles of elevation, depression, and more.
Find angles and lengths in 3D shapes using combined Pythagoras and trigonometry.
Learn exact values for sin, cos, and tan of 0°, 30°, 45°, 60°, and 90°.
Use a/sin A = b/sin B = c/sin C to find sides and angles in ANY triangle.
Use a² = b² + c² - 2bc cos A to solve triangles with no right angle.
Find the area of any triangle using the formula Area = ½ab sin C.
Tackle complex multi-step problems requiring both sine and cosine rules.
Combine bearings with trigonometry for navigation and surveying problems.
Sketch and interpret graphs of sine, cosine, and tangent functions.
Master all trigonometry topics with exam-style questions and mixed practice.
Ready for more geometry? Continue to Section 10 for transformations and vectors, or revisit Section 8 for foundational geometry.