



observing that according to the 



may bo geometrically rontosentod by 

 dangle having for iu da* 

 presents the force ana for its vertex the point 

 about which moments are taken. For f**mplf, wo may 

 theorem which we hare already deduced. 



'he algebraical turn of the momente of two fttmmmmt 

 /i respect to any point in the plane containing the two 

 force* tf equal to the moment of the resultant of the lwofore*e. 



represent two component forces ; 

 parallelogram and draw 

 diagonal AD representing the 



(1) Let 0, the point about 



nts are to bo 



taken, fall without the angle 



//.I' ' .'.mi that which is 



v oppos .loin 



The triangle OAC having for its base AC and for its 

 .: the jKTpendu-ulnr from on AC IB equivalent to a 

 .^ACfarilB base and for its height the perpen* 

 ir from B on A(\ together with a triangle havin. 

 - base and for its height the perpendicular from Ooi 



u since BD is cnual and parallel to A (\ and the 



from on AC is equal to the perpendicular 



<) on BD together with the perpendicular from B on AC. 



-, adding the triangle A OB, wo have 



that is, the moment of AC+ the 



of AB-ti* mo- 



4-3 



