1. The problem statement, all variables and given/known data With the diagram and the data answer the question: What is the magnitude of A + B? http://i995.photobucket.com/albums/af79/huybinhs/w.gif DATA: theta1 = 33.7 deg, theta2 = 141.9 deg , A = 3.6cm, B =8.3cm. 2. Relevant equations This is an example of vector addition. You have to add the x and y components independently and then use the theorem of Pythagoras. The figure is not to scale. 3. The attempt at a solution I did as follow: Ax = 3.6 * cos(33.7) = 2.995 m Ay = 3.6 * sin(33.7) = 1.997 m Bx = - 8.3 * sin (141.9) = -5.121 m By = 8.3 * cos 141.9 = -6.532 m A+B = sqrt[ (2.995 -5.121)^2 + (1.997 - 6.532)^2 ] = 5.001 = answer, but it's showing wrong!!! Could u tell me what's wrong? Thanks!