...interior angles. How do the angles of any pair compare in size ? Theorem. If two parallel straight lines are cut by a transversal, the alternate interior angles are equal. /E Data: Any two parallel straight lines, as AB and CD, cut by a trans- Aversal, as EF, in the points...

...interior angles. How do the angles of any pair compare in size ? ~ Theorem,. If two parallel straight lines are cut by a transversal, the alternate interior angles are equal. Data: Any two parallel straight lines, as AB and CD, cut by a trans- Aversal, as EF, in the points...

...point in the perpendicular to the extremities of the line are equal. 4. Demonstrate: If two parallel lines are cut by a transversal the alternate Interior angles are equal. 5. Demonstrate: The sum of the interior angles of any convex polygon is equal to twice as many right...

...toincides with• CF, to which PQ is _L). PROPOSITION }£fy&. THEOREM 124. // two parallel straight lines are cut by a transversal, the alternate interior angles are equal. H Given the || lines AB and CD cut by the transversal PQ at the points G and E respectively. To prove...

...alternate interior angles are equal if, and only if, those two lines are parallel. [Half of Dl, 2.1 When two lines are cut by a transversal, the alternate interior angles are unequal, if nnd ouly if, the lines are not parallel. (Synonymous to 1.) 2. When two lines are cut by...

...How are AB and CD related ? Why ? § 102. Therefore — PROPOSITION XXI. in. Theorem. If two parallel lines are cut by a transversal, the alternate interior angles are equal. MC /E -R NB D Let MR and NP represent two parallel lines cut by the transversal AB. Suggestion 1. Through...

...straight lines parallel to a third straight line are parallel to each other. 153. If two parallel straight lines are cut by a transversal, the alternate interior angles are equal. 154. Corollary 1. If two parallel straight lines are cut by a transversal, any pair of corresponding...

...the same line are parallel. 6. Two lines parallel to the same line are parallel. 7. If two parallel lines are cut by a transversal the alternate interior angles are equal, the corresponding angles are equal, and the interior angles on the same side are supplementary. 8....

...Then BE II D'F. § 364. 6. In A BEO and A OFD1, BO = OD'. By 3. 7. Z QBE = Z OD'F. (If two parallel lines are cut by a transversal, the alternate interior angles are equal.) § 75. 8. ZEOB = ^D'OF. (If two straight lines intersect, the vertical angles are equal.) § 44. 9....

...forever remain an axiom unless some other equivalent proposition is assumed. 97. THEOREM. // two parallel lines are cut by a transversal, the alternate interior angles are equal. Given /j II 72 and cut by t. To prove that Z 1 = Z 2. " — rr-y L\2/ — - _7 Proof: Suppose Z 2 not...