Adiagonal support beam is attached to the gate of a fence as shown. which angles must be congruent in order for the top and bottom sides of the gate to be parallel?
a) ∠ 1 and ∠ 2
eliminate
b) ∠ 3 and ∠ 4
c) ∠ 1 and ∠ 4
d) ∠ 1 and ∠ 3

Amass weighing 16 pounds stretches a spring 8/3 feet. the mass is initially released from rest from a point 2 feet below the equilibrium position, and the subsequent motion takes place in a medium that offers a damping force that is numerically equal to 1/2 the instantaneous velocity. find the equation of motion if the mass is driven by an external force equal to f(t)=cos(2t).