PLEASE HELP A quadrilateral with four congruent sides and one pair of opposite angles each measuring 60° must be
a
A. rhombus
B. rectangle
C. trapezoid
D. square

What situation is an example of an observational study

An automated water dispenser fills packets with one liter of water on average, with a standard deviation of 5 milliliter. the manual says that after a year of operation the dispenser should be tested to see if it needs recalibration. a year later a number of filled packets are set aside and measured separately. it is found that the average packet now contains about 0.995 liters. does the dispenser need calibration? explain your answer.

Acourt reporter is transcribing an accident report from germany. the report states that the driver was traveling 80 kilometers per hour. how many miles per hour was the driver traveling?