Using {0,1,3,4,5,6,9}, how many four-digit numbers with different digits can be produced between 4000 to 5000, if the numbers must be divisible by 9?

Solve the triangle. a = 21°, c = 105°, c = 5

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?

Corresponding angles are a. always b. sometimes c. never congruent