Me with this math question. i do not fully understand.

Well, the area of the rectangle can be found by multiplying the base by the height.  10 is the width and 16 is the height, so the area of the rectangle is 160. However, we need to find the area of the semicircle. To do that, we need to find the radius, which can be found by looking at the width at the side. Half of 16 is 8, and we use the area formula and get around 200 centimeters. However, it's a semicircle, therefore we need to divide 200 by 2 in which we get 100. 160+100 equals 260 centimeters. 260 centimeters is the answer.