Books can have 2-D drawings of 3-D shapes. View-through geometric solids helps to understand what the 3-D shapes are really like.
Building the prisms and pyramids can be done with simple things like clay and tooth picks. Magnetic sticks and balls toys can be used as well.
Match link cubes can be used to build structures and visualize side views.
3-D printing helps as well, and using tinkercad is useful for understanding 3-D viewing.
Kids like these playful math lessons.