Module 4 Foundations of Trigonometry

Benchmark - Radians & Arc Length

1. Find the length of the arc which subtends an angle of 4.2 radian at the centre of a circle of radius 6.3 cm. (1 mark)

2. Find the length of the arc which subtends a sector angle of 225° in a circle with radius 3.7 cm. (1 mark)

3. A pendulum 6 cm in length swings and makes an arc of 15 cm. Find the size of the angle through which the pendulum swings (in radian and degree measure). (2 marks)

4. Select A,B,C,D, or E. How many radians in 210°? (1 mark)
A) pi/6 B) 6pi/7 C) 7pi/6 D) 8pi/3 E) 5pi/4