I thought this was fun.

This was my first try:

Your inaccuracy by category:

Parallelogram 2.2 2.8 8.1

Midpoint 11.7 5.8 7.1

Bisect angle 0.0 4.1 4.8

Triangle center 3.4 7.6 7.3

Circle center 4.1 4.5 5.4

Right angle 0.4 2.4 1.8

Convergence 5.8 5.1 4.1

Average error: 4.69 (lower is better)

Then I managed:

Your inaccuracy by category:

Parallelogram 2.2 3.6 2.2

Midpoint 8.6 2.2 1.0

Bisect angle 1.2 3.2 2.1

Triangle center 1.3 1.1 3.8

Circle center 0.0 1.4 3.6

Right angle 0.6 2.2 1.8

Convergence 4.5 1.0 3.2

Average error: 2.42 (lower is better)

I'm going to try again and see if I can get under 2 when I have the time.