Chapter 1.2, Problem 5E

Which of the following conditional sentences are true?
(a) If triangles have three sides, then squares have four sides.
(b) If hexagons have six sides, then the moon is made of cheese.
(c) If $\text{7}+\text{6}=\text{14}$ , then $\text{5}+\text{5}=\text{1}0$ .
(d) The Nile River flows east only if 64 is a perfect square.
(e) Earth has one moon only if the Amazon River flows into the North Sea.
(f) If Euclid’s birthday was April 2, then rectangles have four sides.
(g) 5 is prime if $\sqrt{2}$ is not irrational.
(h) $\text{1}+\text{1}=\text{2}$ is sufficient for $\text{3}>\text{6}$ .