Watch comprehensive video reviews for most units, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
2D & 3D Geometry
Watch comprehensive video reviews for 2D & 3D Geometry, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
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SL Core 3.2
The previously found formula for area
applies to any pair of sides and the angle between them. Since the area is the same no matter which sides we use:
Multiplying everything by 2 and dividing by abc:
Flipping the numerator and denominator gives the form that appears in the formula booklet:
The sine rule is primarily used when we know two angles and a side.
Example
Find the side x in the triangle below.
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The sine rule works with angles and the side opposite them, so we need the angle opposite x. Since the angles in a triangle add to 180°:
The sine rule tells us that
SL Core 3.2
The previously found formula for area
applies to any pair of sides and the angle between them. Since the area is the same no matter which sides we use:
Multiplying everything by 2 and dividing by abc:
Flipping the numerator and denominator gives the form that appears in the formula booklet:
The sine rule is primarily used when we know two angles and a side.
Example
Find the side x in the triangle below.
Powered by Desmos
The sine rule works with angles and the side opposite them, so we need the angle opposite x. Since the angles in a triangle add to 180°:
The sine rule tells us that