Shot Put circles

This task is about calculating areas of circles and sectors of circles.

A shot-put throwing circle and throwing area are shown in this diagram. 

a) The diameter of the throwing circle is 2.5 m. Calculate the area of the throwing circle.

Show your working here:
 
 
 
 
 
 
 
The area of the throwing circle is __________ m2 (to 1 d.p)

 
b) Calculate the area of the throwing area (sector AOB) if it has a radius of 30 m and an  angle AOB = 40o.

Show your working here:
 
 
 
 
 
 
 
 
Shaded area __________ m2 (to the nearest square metre)