One lap around a dirt track is 1/3 miles it take bryce 1/3 hour to ride one lap what is bryce unite rate in miles around the track

What is the number 321,000,000 in scientific notation? also what is the number? ?

Evaluate cos2θ for cosθ = square root of 3/2

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?