What is the area of 4cm 9cm 7cm 5cm?

Since there are 4 lengths given, the shape could be a quadrilateral. Unfortunately, the lengths of the sides is not enough information to determine the shape of a quadrilateral. As an illustration, consider a square of sides 10 cm. Its area is 100 cm2. But it can be "distorted" into a rhombus with the same sides but the area can be reduced to as close to 0 as you like.

Four linear measures could also mean that it is a 4-dimensional cuboid in hyperspace or some other shape in 2 or 3 dimensions. But since these shapes cannot be determined, it is not possible to find an answer to the question.