Step-by-step explanation:
the perimeter is the easiest, really. we only need to add all side lengths. there is nothing else to the perimeter calculation.
so,
perimeter = 6.5 + 2.5 + 6 = 9 + 6 = 15 ft.
area is also relatively easy for right-angled triangles, because the sides that enclose the 90° angle, act also as height of the triangle to each other.
so, it is a half-rectangle, and we only need to multiply these 2 sides (not including the Hypotenuse) and divide this by 2.
area = 6×2.5/2 = 3×2.5 = 7.5 ft²
