Preheat oven to 400° F.
Peel cucumber; chop 1/4 and cut the remaining into slices.
Place yogurt, spinach, chopped cucumber, salt, and pepper into a food processor or blender; process about 1 minute until smooth. Refrigerate until ready to serve.
Cut each pita into 8 wedges, then arrange on a baking sheet in a single layer. Spray with cooking spray then sprinkle lightly with garlic powder.
Bake for 5 minutes or until lightly golden and crispy.
Serve chips and dip with cucumber slices on the side (or save cucumbers for a future meal or snack).