Answer:8sqrt 2 or sqrt 128
Step-by-step explanation:
We can use the Pythagorean Theorem. Since the ladder is leaning against the wall, it is the hypotenuse. It is also 4 feet away from the wall so 12^2-4^2=b^2 b^2=128 so b=8sqrt 2 or sqrt 128.
So a mile has 5280 feet.
21,129/5280= 4 mph
multiply
4 x 2 = 8 miles in 2 hours
1/8 of the lawn in 1/4 of an hour. That mean you would need a whole hour to do 4/8 or 1/2 of the lawn. So you would need two hours to do the whole lawn.
You would need to convert the centimeters to meters, there are 100 centimeters in a meter so you would need to divide 85 by 100 then you just need to add the sides up. The final answer should be 15.2 meters.
Number 2 is 990 because the numbers are 9, 10, and 11.