The rigid bars a c and e d b are pinned to a wall at a and e , respectively, and pinned together at b . bar a c is subjected to a triangular distributed load with w = 4 k n / m . consider the following dimensions: a = 680 m m , b = 85 m m , c = 510 m m , d = 170 m m and l = 1699 m m matlab input: a = 680; b = 85; c = 510; d = 170; l = 1699; w = 4; determine the reaction force at pin a , r a . input the reaction as vector components according to the included coordinate system.'