<s id="A18-2.36.01">36 We want to find the same for the quadrangle.</s>
<s id="A18-2.36.02">Let thus the given quadrangle be <abgd>.</s>
<s id="A18-2.36.03">Let us draw <bd> and bisect it at point <e>, connect the two points <a>, <e> and <e>, <g> respectively and divide the connecting lines at points <z>, <h>, so that <az> is twice the amount of <ze> and <gh> twice the amount of <he>, then the center of gravity of the triangle <abd> is at <z> and the center of gravity of the triangle <bdg> at point <h> and we do not find any difference, if we imagine the entire weight of the triangle <abd> at point <z> and as well the weight of the triangle <bgd> at point <h>.</s>
<s id="A18-2.36.04">Thus the line <zh> is a balance at the ends of which are these two quantities.</s>
<s id="A18-2.36.05">If we now divide the line <zh> at point <q> so that <qh> relates to <zq> like the load <z>, i.e., the weight of the triangle <abd>, to the load <h>, i.e. the weight of the triangle <bdg>, then the point <q>, at which the two loads are keeping the balance, is the center of gravity of this quadrangle.</s>
