Hello!
The formula is given to you. :)
C = 3.14 • D (diameter; line across a circle that cuts it in half)
C = 3.14 • 21 = 65.94 inches.
Hope I helped! Also, I hope I didn’t answer this too late. ;)
~Destiny ^_^
(1) The train travels 4 miles per gallon.
(2) The slope of the graph is 
Explanation:
(1) The miles that train travels per gallon is given by

Dividing, we have,

Thus, the train travels 4 miles per gallon.
(2) To determine the slope, let us consider two points from the graph.
The coordinates are
and 
Thus, substituting the coordinates in the slope formula, we get,

Simplifying, we have,

Thus, the slope of the graph is 
In the problem stated,we are asked to convert 1.42 g/cm^2 to mg/mm^2 . From the units given, 1 gram is equal to 1000 milligrams and 1 centimeter is equal to 10 millimeters. We square the second conversion to take consideration of the squaring of cm. in this case, the conversion is 1.42 g/cm2 * (1000 mg/1g)*(1 cm / 10 mm)^2 equal to 14.2 g/mm2
Answer:
A and c
Step-by-step explanation:
805043 would be the answer i believe