The angles must add to 180 degrees.
Since the angles are in the ratio 7:9:4, their measures are not 7, 9, and 4 since 7, 9, and 4 do not add to 180. If you multiply 7, 9, and 4 by the same number, the new numbers will be in the same ratio. Since we do not know what that number is, we can use x for it.
Multiply 7, 9, and 4 by x to get
7x, 9x, and 4x.
Now add them and set equal to 180.
Then solve for x.
7x + 9x + 4x = 180
20x = 180
x = 9
Now that we know x equals 9, substitute x with 9 and evaluate 7x, 9x, and 4x to find the actual angle measures.
7x = 7 * 9 = 63
9x = 9 * 9 = 81
4x = 4 * 9 = 36
The angles measure 63, 81, and 36 degrees.
Length of a line given two points is given by:

Since |AB| = |CD|, points A, B, C, D form a parallelogram.
The volume of a cone is equal to 1/3•pi•r^2•h. If you want to find the volume of something in terms of pi, you must multiply all other numbers and leave the answer without multiplying the pi in.
In this case, the radius is equivalent to 2mi and the height is equivalent to 7mi. This means….
r^2=4
h=7
Now plug in the numbers into the formula for the volume of a cone.
1/3•4•7•pi
28/3pi
The answer is 28/3 pi.