Side AB is parallel to side DC so the alternate interior angles, angle ABD and angle CDB, are congruent. Side AB is equal to side DC and DB is the side common to
triangles ABD and BCD. Therefore, the triangles ABD and BCD are congruent by SAS
postulate. By CPCTC, angles DBC and ADB are congruent and sides AD and BC are
congruent. Angle DBC and angle ADB
Therefore, AD is parallel and
equal to BC. Quadrilateral ABCD is a parallelogram because its opposite sides are
equal and parallel.

For a field trip to the zoo, 4 students rode in cars and the rest filled nine busess. how many students were in each bus if 472 students were on the trip

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function. a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.