This colourful powerpoint uses animations and photographs to introduce or revise the vocabulary needed for working with circles e.g. radius, diameter, circumference, centre, circular, semicircle. There is also an accompanying worksheet. Slides require students to draw circles with given dimensions and perform calculations based on circles fitting inside other shapes and vice versa.
The images and animations can also be used to revise area calculations, metric unit conversions, symmetry ( using photographs of car badges for instance ) and locus work. The hardest problem requires a knowledge of Pythagoras to solve it. The slides have notes and suggestions accompanying them.
See my other resource 'Circles - vocabulary' which follows on from this one to introduce chords, sectors, segments, arcs and tangents.