can someone please tell me how to do this (my homework)?

Question

its a GCSE question, that we are supposed to be practising but i dont have a clue the question @: http://freewebs.com/worldoffunn

theline Bc isnt a diameterbecause it dosent pass through the origin (centre)

Answer 1

a> find the angle bac
the line BC is diameter= 2*r=2*3=6
use cosine law
a^2=b^2+c^2-2bccosA
cosA=(b^2+c^2-a^2)/2bc=( 9+9-36)/(2*3*3)
cosA=-18/18= 180 degree
b> use sector area
A=1/2*Qr^2
A=1/2 pi*9 because Q is in radian
c> you figure the entire area circle
A=pir^2=pi*9
the area of the rest= entire are- area sector
A=9pi-9/2 pi= 4.5pi.
d. i am notsure the answer
area of square=50^2=2500
9pi/2500=.0113 sqare sheet
good luck