Document page
mathematicsprinted 86 · PDF 87
165 pagesrevision 46935
printed 86 · PDF 87
Page image rendered from the stored file at 110 dpi; it sharpens as you zoom. Outlines are placed from each region’s stored position on the page (595 × 842 pt).
readable
Source of this text: embedded text layer. The better of the embedded text and OCR is kept.
86
Parallelogram
a×h
2×a+2×b
Circles, Arcs, and Sectors
Circumference: The circumference of a circle is its curving perimeter.
Diameter: The distance from one point on a circle’s circumference to another,
and passing through the centre of the circle. (Denoted by d)
Radius: The distance from any point on the circumference to the centre.
(Denoted by r)
Chord: A line connecting any two points of a circumference.
π: A constant that represents the ratio of any circle’s circumference to its
diameter. π ≈ 3.142.
A circle with key features labelled
Formula for circumference of a circle: 2πr
Formula for area of a circle: πr2
Semicircle: A half-circle, as illustrated below
A semicircle