Answer is: the approximate bond angle in cyclobutane is 90 degrees and in cyclopentane is 108 degrees.
Cyclobutane has single covalent bonds, the actual C-C-C bond angle is 88 degrees, because it has a slightly folded form to relieve some torsional strain.
Cyclopentane also has single covalent bonds and it has an unfixed puckered shape that undulates up and down.