Reteaching
... If a || b and b || c, then a || c. Lines a, b, and c can be in different planes. Theorem 3-9: If two lines are perpendicular to the same line, then those two lines are parallel to each other. This is only true if all the lines are in the same plane. If a ⊥ d and b ⊥ d, then a || b. Theorem 3-10: Per ...
... If a || b and b || c, then a || c. Lines a, b, and c can be in different planes. Theorem 3-9: If two lines are perpendicular to the same line, then those two lines are parallel to each other. This is only true if all the lines are in the same plane. If a ⊥ d and b ⊥ d, then a || b. Theorem 3-10: Per ...
problems
... In 1733 there appeared the book Euclid Vindicated of All Flaw by the Jesuit priest Gerolamo Saccheri. In it the author purported to prove Euclid’s Fifth Postulate as a theorem. We now recognize basic flaws in his argument at certain crucial steps. However, the book was and is important in the develo ...
... In 1733 there appeared the book Euclid Vindicated of All Flaw by the Jesuit priest Gerolamo Saccheri. In it the author purported to prove Euclid’s Fifth Postulate as a theorem. We now recognize basic flaws in his argument at certain crucial steps. However, the book was and is important in the develo ...
