Divide in half the total of the start and end coordinates of the extreme points of the segment along each axis to determine the coordinates of the midpoint along this axis. For example, suppose the cut is placed in a three-dimensional coordinate system XYZ and the known coordinates of its extreme points A(Xa,Ya,Za) and C(Xc,Yc,Zc). Then the coordinates of its midpoint E(Xe,Ye,Ze) can be calculated by the formula Xe=(Xa+Xc)/2, Ye=(Ya+Yc)/2, Ze=(Za+Zc)/2.
Use any of the calculators, if you average the coordinate values of the endpoints of a segment in mind is not possible. If you do not have such a gadget, use a software calculator from Windows. It can be run if click "start" to open the main menu system. In the menu go to "Standard", then to "Utility" and then in the section "All programs", select "Calculator". You can do without the main menu if you press the key combination WIN + R, type calc, then press Enter.
Summarize in pairs the start and end coordinates of the extreme points of the segment along each axis and divide the result by two. Interface software calculator simulates an ordinary calculator, and numeric values and symbols of mathematical operations like clicking the mouse cursor on the screen, or pressing the corresponding keys on the keyboard. Any difficulties with these computations should not occur.
Record mathematical operations in text form and enter them in the search query box on the main page of Google, if for some reason can't use a calculator, but have access to the Internet. This search engine has a built-in multi-function calculator to use which is much easier than any other. Here there is no interface with buttons to enter all data must be in text form in a single field. For example, if you know the coordinates of the endpoints of the segment in the three-dimensional coordinate system A(51,34 17,2 of 13.02) and A(-11,82 7,46 33,5), then the coordinates of the midpoint of a segment C((51,34-11,82)/2 (17,2+7,46)/2 (13,02+33,5)/2). Typing in the search query box (51,34-11,82)/2, then (17,2+7,46)/2 and (of 13.02+33,5)/2, you can use Google to obtain the coordinates C(19,76 of 12.33 23,26).