Step-by-step explanation:
the area of such a regular shape with n sides is the sum of n isoceles triangles (meaning each triangle has equally long legs) from the center to 2 neighboring corners.
the area of a triangle is
baseline × height / 2
so, for these triangles that means
shape side length × apothem / 2
in our case, n = 6, the side length = 5 cm, the apothem is 4.3 cm. and we get as total area
6 × 5×4.3 / 2 = 3 × 5 × 4.3 = 15 × 4.3 = 64.5 cm²
