PTG Test. Five geometry problems of different difficulty levels were
selected and modified for this test. Mathematics textbooks and previous
examination papers were the first source of these problems that were
subsequently modified with guidance from mathematics teachers. All problems were well-structured proof problems. Our decisions to select or
modify these problems were guided by (a) richness of embedded
geometric knowledge and (b) multiple reasoning steps involved in the
development of proofs. Figures 1 and 2 below are two of the problems
that appeared in this test.