Which properties are best used prove a quadrilateral is a parallelogram?
a) Diagonals are congruent and perpendicular.
b)Diagonals are congruent.
c) Diagonals bisect and are perpendicular.
d) Diagonals bisect.

Choose the more precise measurement. 26.4 cm or 8.39 cm

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.

The given diagram shows the parts of a right triangle with an altitude to the hypotenuse. using the two given  measures, find the other four.