Since GO and AL are parallel to each other, we can use the same side interior theorem to figure out angle A and L. Let's focus on GA first. We know that same side interior angles are supplementary (sum is 180 degrees). We know angle G is 40 degrees, so to figure out angle A, you do 180-40 which equals 140. So angle A is 140 degrees. You repeat this process for OL and you should also get 140 degrees for L.
