ABC is a right angled triangle at A , AD perpendicular on BC , AB = 4 cm , CD = 5 cm , ACxAD =
AC x AD can be represented as the area of the triangle ABC.
The area of a triangle is given by the formula: 1/2 x base x height.
In this case, the base of the triangle is AB = 4 cm and the height is CD = 5 cm.
So, the area of triangle ABC = 1/2 x 4 cm x 5 cm = 10 cm^2.
Therefore, AC x AD = 10 cm^2.