Calculate the length of the first vector using the formula:
sqrt((X2 - X1)^2 + (Y2 - Y1)^2)
"Sqrt" is an abbreviation for the root square math operation.
In our example, the first vector length is:
sqrt((4-2)^2 + (6 - (-3))^2) = sqrt(4 + 81 ) = 9.22
Calculate the length of the second vector using the same formula as in Step 1. In our example, the second vector length is:
sqrt((7 - 2)^2 + (5 - (-3))^2) = sqrt(25 + 64 ) = 9.43
Calculate cosine of the angle using the function "cos" on your calculator. In the example, cos(24) is 0.9135.
Multiply the first vector length, the second vector length and the cosine of the angle to calculate VDP. In our example, VDP equals:
9.22 * 9.43 * 0.9135 = 79.42