A tablet case is supported at the back. the measure of the slant angle of the tablet can be changed, but m∠2 = m∠3 for any slant that is chosen.

Part A: A user adjusts the case so that m∠2 = 42. What are the measures of the other angles?

Part B: Is it possible to slant the tablet case so that m∠1 = m∠5? If so, explain how. If not, explain why it is not possible.

Part C: A user wants to slant the tablet case so that m∠1 = 2(m∠5). What should the measure of each of the five angles be?