The midpoint is 15 hope i helped
Original:350 discount:87.50 off new price: 262.5
We have two triangles with base 9ft and height 12.3ft and two triangles with base 11ft and height 11.9ft.
The formula of an area of a triangle:

Triangle #1:
b = 9ft and h = 12.3ft. Substitute:

Triangle #2:
b = 11ft and h = 11.9ft. Substitute:

The Lateral Area:

<h3>Answer: B. 241.6 ft².</h3>
If this is with remainders then it is 39 with a remainder of 3, and if this is with decimals then it is 39.6