Ihave been stuck with this one, and i would like to how to solve this.
in each case, determine whether line ab is parallel or perpendicular to cd.
(a) a(0, 0), b(0, 1), c(0, 0), d(1, 0).
(b) a(0, 1), b(2, 3), c(4, 5), d(6, 7).

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Scenario: susan wants to make 2 square flags to sell at a crafts fair. the fabric she wants to buy is 3 meters wide. she doesn't want any fabric left over. what's the least amount of fabric she should buy? question: which equation will susan solve her problem? note: let x represent the length of 1 side of the flag. options: 1) 2x^2 = 4x 2) 8 +2x = 2(4x) 3) 2 * 2 = 4 * 2 4) 4x^2 -2x = 0