Answer: 48 square cm
Step-by-step explanation:
From the center point, draw connecting segments to each corner of the octagon. This forms a "pizza" of sorts. It's not round but you get the idea.
Each of the pizza slices is a triangle with base 4 and height 3
Let's find the area of one triangular slice.
area = 0.5*base*height = 0.5*4*3 = 6 square cm
Because there are 8 of these identical pieces, the total octagonal area is 8*6 = 48 square cm