1. 1 Press Ctrl-A ©G Dear 2009 – Not to be sold/Free to use Arc Length Stage 6 - Year 12 General Mathematics HSC

2. 2 Arc Lengths (1/3) The circumference of a circle can be found using either of the formulas: C = 2πr.C = πd 3cm C = π x 3 ≈ 9.4 cm C = 2 x π x 7 ≈ 43.0 cm 7cm

3. 3 x 2 x π x r Arc Lengths (2/3) The arc length is calculated using the formula: l = θ 360 Fraction of the Circumference Circumference x π x d 50 360 50 o 3cm l = x 2 x π x 3 θ ≈ 2.6 cm

4. 4 Arc Lengths (3/3) Find the distance between two towns on the equator that have 6 o between them. 6o6o 6400 km 6 360 l = x 2 x π x 6400 ≈ 670 km Radius of the Earth