A circle has radius of 6cm. A sector has an arc length of 8.4cm. The angle at the centre of the sector is θ. Calculate the value of θ.

Using .....  S = rΘ   where S is the arc lengrh and r is the radius, we have.....

8.4 cm = 6 cm * Θ      divide by 6 cm on each side

8.4 / 6  = Θ = 1.4 rads  = about 80.21°