A farmer has a field in the shape of a trapezoid, formed by three congruent isosceles triangles, as shown below. He wants to plant vegetation in the green shaded area and pour concrete in the remaining area

now, we're assuming the trapezoid is an isosceles trapezoid, namely AD = BC, and therefore the triangles are twins.

incidentally, b is the height of the trapezoid and likewise is also the altitude or height of the concrete triangle.

so we can simply get the area o the trapezoid, notice the bottom base is a+185+a, and then get the area of the concrete triangle and subtract the triangle from the trapezoid, what's leftover is just the vegetation area.

Hope this help doe

Step-by-step explanation:

boxplot