Vectors, coordinates, circles, and an introduction to solid geometry. How to Use Solutions (GDZ) Without Getting Stuck
Quadrilaterals (parallelograms, trapezoids), the Pythagorean theorem, and the concept of area.
Geometry isn't about the final answer (like "x=5"); it’s about the proof . Use GDZ to check if your deductive steps (the "Because... Therefore..." chain) match the formal requirements.
Many students mix up the three signs in 7th grade. GDZ can help you see which specific sides or angles you need to "match" to prove equality.