Se considera trapezul ABCD cu unghiul A=B=90 de grade, AD mai mic BC. punctul e este situat pe latura AB, astfel incat unghiul AED=BEC. paralela prin B la de intersecteaza EC in puncrul F, iar unghiul BCE=30 de grade. aratati ca: a) triunghiulBEF este echilateral;
b) punctul Fest emijlocul segmetului CE

Using the given statements, state whether the conditional statement is true or false. p: 2 + 2 = 4 q: 7 + 1 = 7 is p q true or false?

Gravel is being dumped from a conveyor belt at a rate of 25 ft3/min, and its coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are always equal. how fast is the height of the pile increasing when the pile is 14 ft high? (round your answer to two decimal places.) ft/min

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.