Week 13 Penny for Thoughts

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We make a model of a penny farthing bicycle shown above such that the small circle centred at A with radius, r  and the large circle centred as B with radius, R  both share a tangent with the  x axis and  y axis and also share a tangent at point C.

Find the value of R/r.

Teacher notes:

Level of difficulty:  Accessible for HL students

Syllabus knowledge required:  Pythagoras or similar shapes.

This would be a good starter when doing geometry – students could also explore how this can be plotted on Geogebra and think about possible extensions to create an exploration topic.

You can download a pdf of the solution here.

Published by Ibmathsresources.com

Maths teacher

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