Energy is conserved. You can't create it and you can't destroy it. If there's nothing going on here that robs energy from the pendulum**, then it must have the same amount of energy at every point in its swing as it has at every other point.
If it has 894 J of energy at the highest point ... where its energy is all gravitational potential energy, then it must have the same 894 J of energy at the lowest point, where its energy is all kinetic energy.
** Examples of things that could be going on that would rob energy from the pendulum:
-- air resistance
-- a fly lands on it while it's swinging
-- somebody breathes on it
-- it bumps into something
-- friction at the top pivot
-- etc.
There's ALWAYS something. If it isn't one thing, then it's something else. That's why pendulums always stop eventually.
