3) . Ddraw the radius to the right side of the chord. So you formed a right triangleNow let's apply Pythagoras
3.6² + 5.5²= x² ==> x = 6.57 ≈ 6.6
4) same logic but the other leg = x/2 you will find
x² = 133/4 & x =5.766≈ 5.8
5) arc ab = arc de (1st proposition)
