Using the Disk graphics primitive II

Question

I ask again to clarify a couple more things

How do I write the disk primitive to calculate these cases

Cases

follow this link 1 reply from @kglr

thanks

Using the Disk graphics primitive

Answer 1

Hope the following clarifies how quarter disks centered at {0,0}, {1,0}, {1,1} and {0,1} can be constructed using a single parameter:

Manipulate[Graphics[{EdgeForm[{Opacity[1], Thick, Orange}], Opacity[.3], 
   Orange, Disk[{0, 0}, 1, {0, θ}], 
   EdgeForm[{Opacity[1], Thick, Blue}], Blue,  Disk[{1, 1}, 1, {-Pi, -Pi + θ}], 
   EdgeForm[{Opacity[1], Thick, Green}], Green, Disk[{1, 0}, 1, { Pi, Pi - θ}], 
   EdgeForm[{Opacity[1], Thick, Magenta}], Magenta, Disk[{0, 1}, 1, { 3 Pi/2, 3 Pi/2 + θ}], 
   FaceForm[None], EdgeForm[Gray], Rectangle[{0, 0}, {1, 1}]}, 
  PlotRange -> {{0, 1}, {0, 1}}],
{θ, 0, Pi/2, Pi/64}]