Answer:
15 minutes
Step-by-step explanation:
Betty mows at 3 times the speed that Bullwinkle does, so is equivalent to having 3 Bullwinkles in her place. That makes the lawn get mowed as though 4 Bullwinkles were working, so it will take 1/4 the time it takes Bullwinkle to mow the whole yard. 1/4 of 60 minutes is 15 minutes.
Working together, Betty and Bullwinkle will take 15 minutes to mow the lawn.
-1 is your answer, if that is what you want...
Firstly , we need to draw diagram
we are given
opposite =300
adjacent =750
now, we can use tan formula

now, we can find x

we get

so,
angle of depression is 21.8 degree.....Answer
The Circumference would be 1256.637 and the diameter would be 400