Aa′ = 33 m and bc = 7.5 m. the span is divided into six equal parts at e, g, c, i, and k. find the length of a′b.

The correct answer for the question that is being presented above is this one: "18.12."
The image of this triangle is an isosceles triangle with the base being 33m (from angle A to angle A') and the right leg is 7.5 m long (BC) the span or width of the triangle is divided by 6 vertical lines with equal distances from eachother. so we need to find the length of the left leg AB.