Stage: 5 Challenge Level: 
Why do this problem?
It provides experience of geometrical thinking,applying only the geometry of right angles triangles and the formula for arc length.Possible approach
Sugggest the learners draw a neat diagram and mark in everything they know and can deduce from the diagram.Key question
How do we split the belt into sections for which the lengths can be calculated?Forces. Pythagoras' theorem. Short problems. Long problems. Sine. Arcs, sectors and segments. engineering. Perimeters. Complex numbers. Tangents.
Published June 1998.
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