Step-by-step explanation:
the answer is the area of the big triangle.
the area of a triangle is
baseline × height / 2
as the inner triangle is splitting the sides of the big triangle in half, that applies also to the height (principle of similar triangles).
so, the baseline of the large triangle is 2×6 in = 12 in.
and the height of the large triangle is 2×5.2 in = 10.4 in.
and so, the whole area (= how much wrapping paper was used) is
12 × 10.4 / 2 = 6 × 10.4 = 62.4 in²
