Final answer:
Bones get their strength and rigidity from a combination of factors. The bone matrix, composed of collagen fibers and inorganic salt crystals, gives bones their hardness and strength. The collagen fibers also provide flexibility to prevent bones from becoming brittle.
Step-by-step explanation:
Bones get their strength and rigidity from a combination of factors. The bone matrix, composed of collagen fibers, provides a surface for inorganic salt crystals to adhere. These salt crystals, including hydroxyapatite, give bones their hardness and strength. At the same time, the collagen fibers provide flexibility to prevent bones from being brittle. The combination of these factors allows bones to be strong and rigid while still being able to withstand stress and movement.