In the straightedge and compass construction of the perpendicular line below, how do you know that EF 1 GH?
A. The angles at the intersection of the two lines can be proven to be
congruent and supplementary, so they meet at a right angle and
the lines are perpendicular.
B. The angles at the intersection of the two lines can be proven to be
congruent and complementary, so they meet at a right angle and
the lines are perpendicular.
C. The angles at the intersection of the two lines can be proven to be
congruent, so they meet at a right angle and the lines are
perpendicular
D. The angles at the intersection of the two lines can be proven to be
sunnlementary so they meet at a richt angle and the lines are
perpendicular

Aking and his army will attempt to capture a fortress. the left and right flanks break off from the main group to attack the west and east guard towers. suppose the left flank has a 60% chance of success and the right flank has a 75% chance of success, independently of one another. if both flanks capture their respective targets, then the king has a 98% chance of successfully taking the fort. if, however, only the left flank captures its tower, the king has an 80% chance of success; if only the right flank succeeds, the king has a 50% chance. if both flanks fail, then the king's chance of capturing the fort drops to 20%. it turns out the king captures the fort. what is the probability that one, and only one, flank was successful (either the left, or the right, but not both)? (round your answer to 3 decimal places)