C.4 Geometry and trigonometry

Use angles in regular two- and three-dimensional structures, including interpreting force diagrams.

Use c.4.1—angles in regular structures to connect the rule to the data and decision in the question.

This matters because c.4.1—angles in regular structures determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.1—angles in regular structures to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.1—Angles in regular structures is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Visualise and represent two- and three-dimensional forms, including two-dimensional representations and force diagrams.

Use c.4.2—representing two- and three-dimensional forms to connect the rule to the data and decision in the question.

This matters because c.4.2—representing two- and three-dimensional forms determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.2—representing two- and three-dimensional forms to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.2—Representing two- and three-dimensional forms is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Calculate triangle and circle areas, circumferences, and surface areas and volumes of blocks, cylinders and spheres.

Use c.4.3—areas and volumes to connect the rule to the data and decision in the question.

This matters because c.4.3—areas and volumes determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.3—areas and volumes to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.3—Areas and volumes is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use Pythagoras' theorem and the angle sum of a triangle, including resultant-vector calculations.

Use c.4.4—pythagoras and triangle angles to connect the rule to the data and decision in the question.

This matters because c.4.4—pythagoras and triangle angles determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.4—pythagoras and triangle angles to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.4—Pythagoras and triangle angles is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use sin, cos and tan in physical problems, including resolving forces into components.

Use c.4.5—trigonometry in physical problems to connect the rule to the data and decision in the question.

This matters because c.4.5—trigonometry in physical problems determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.5—trigonometry in physical problems to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.5—Trigonometry in physical problems is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use small-angle approximations sin θ ≈ θ, tan θ ≈ θ and cos θ ≈ 1 where appropriate, including interference-fringe calculations.

Use c.4.6—small-angle approximations to connect the rule to the data and decision in the question.

This matters because c.4.6—small-angle approximations determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.6—small-angle approximations to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.6—Small-angle approximations is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the relationship between degrees and radians and convert between them.

Use c.4.7—degrees and radians to connect the rule to the data and decision in the question.

This matters because c.4.7—degrees and radians determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply c.4.7—degrees and radians to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: C.4.7—Degrees and radians is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.