Figure 1 below shows the sector AOB AOB\,AOB of a circle.
A student's attempt to find the area of the sector AOB AOB\,AOB is shown below.
Area =12r2θ=12×62×40=720\displaystyle = \frac{1}{2}r^2\theta = \frac{1}{2} \times 6^2 \times 40 = 720=21r2θ=21×62×40=720 cm2^22
Identify the mistake made by the student.
Write out a correct solution.
221 exam-style questions on CCEA A Level Maths 3.4 Trigonometry (A-level only), covering 3.4.1 Trigonometry (A-level only), 3.4.2 Trigonometry (A-level only), 3.4.3 Trigonometry (A-level only), 3.4.4 Trigonometry (A-level only), 3.4.5 Trigonometry (A-level only), 3.4.6 Trigonometry (A-level only), 3.4.7 Trigonometry (A-level only), and 3.4.8 Trigonometry (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.