Answer the following questions on the idea of congruent figures and the use of superposition:
a. (i) Define congruent figures and give one textbook example of a pair of congruent figures.
b. (ii) Explain what is meant by "superposing one figure on another" when testing for congruence of plane figures.
c. (iii) A student claims, "If two figures have exactly the same shape, they must be congruent." Do you agree with this statement? Give a clear reason along with one counter-example or supporting example.