The textbook A New Course in Geometry Andrew Walker James Millar
Each chapter offers a graduated difficulty scale. It starts with "A" exercises (basic computation) and moves to "C" exercises (challenging proofs that require creative thinking). walker and miller geometry book
No standard textbook titled Walker and Miller Geometry exists in major educational publishing. You likely recall the Jurgensen/Brown geometry or a similar classic. If you have a cover image or ISBN, I can help identify it precisely. The textbook A New Course in Geometry Andrew