The diagram illustrates how Stone Age cutting tools changed over time, comparing Tool A (1.4 million years ago) with Tool B (0.8 million years ago) from the front, side and back.
Overall, the later tool appears larger, more symmetrical and more carefully shaped. It also seems thinner and sharper, suggesting a clear improvement in skill and precision.
Tool A has a rough, uneven outline in both the front and back views. Its edges are irregular, and the surface looks patchy, as if only a few large pieces were chipped away. Using the 5 cm scale as a guide, Tool A is just under 10 cm long and around 5 cm wide at its broadest point. From the side view, it looks quite thick, with a rounded profile rather than a blade-like edge.
By contrast, Tool B has a more regular teardrop shape, with a pointed top and a rounded base. The front view shows many smaller flake marks, which creates straighter edges and a smoother overall finish. It is also noticeably bigger – approximately around 12 cm in length and close to 8 cm in width. In addition, the side view indicates a slimmer cross-section, implying a sharper cutting edge than Tool A.