Answer:
75
Step-by-step explanation:
this problem statement tries to confuse us. there is no pi involved - also because there are no round surfaces and edges involved.
what do you think the surface area of such a 4-sided pyramid consists of ?
think !
there are the 4 walls or sides. and then there is the bottom too (if you lift the pyramid up, yes, the "floor" or bottom also belongs to the surface area).
each "wall" or side is actually a triangle.
and the bottom is a square.
what is the area of a triangle (At) ?
At = base length × height / 2 = 3×11/2 = 33/2 in²
what is the area of a square (As) ?
it is a special form of a rectangle, where length = width.
the area of a rectangle (Ar) = length × width.
and the area of a square (As), where length = width is
As = side length × side length = length² = 3² = 9 in²
our pyramid now has 4 "walls", all of the same size, so we need 4 times the area of such a single triangle.
and then add the bottom area.
=> the pyramid surface area (Ap) is
Ap = 4 × At + As = 4×33/2 + 9 = 132/2 + 9 = 66+9 = 75 in²
