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36
0.5×36×2.
A Level · English Medium · Pearson Edexcel · Mathematics
Geometry, measurement and trigonometry readiness
Use vectors, radians and identities to solve constrained geometric problems.
About this lesson and its coverage
Original Kidemy A Level progression. This level has its own text, examples and questions. Curriculum versions share the progression; complete board-specific coverage still needs specification matching and additional material.
Learn the idea
Vector equations must satisfy every component. The scalar product provides an angle relation for nonzero vectors. Radian formulas for sector area and arc length require radian angles. Trigonometric manipulation can introduce exclusions when dividing by a function.
Worked example
For r=4 and θ=1.5 radians, sector area=r²θ/2=12. If a·b=0 for nonzero vectors, their directions are perpendicular.
- Identify the quantities and restrictions.
- Show a method with units or symbols.
- Check and explain the result.
Your written practice
Show your working on paper. Check your answer, then choose Next.
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4
2−4+6.
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-6
k+6=0.
Write in your own words. A guardian or teacher should review this response.
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cosx=0 is itself a valid way for the product to vanish; division excludes it.
List the excluded branch.
Write in your own words. A guardian or teacher should review this response.
Show model answer and explanation
t=2 satisfies both3+2t=7 and −1+4t=7.
Use consistent components.
Progress and browser storage
Notebook challenge, sources and further study
Apply the idea
Solve a vector or sector problem and explain every angle or nonzero restriction.
Review with a guardian or teacher
- Use the stated evidence or givens.
- Show reasoning rather than only a result.
- Review and explain one correction.
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