Ladder and cube

A 1 metre cube has one face on the ground and one face against a wall. A 4 metre ladder leans against the wall and just touches the cube. How high is the top of the ladder above the ground?

Problem

Ladder and Cube printable sheet



A cube (1 metre by 1 metre by 1 metre) has one face on the ground and one face pushed up against a wall.

A 4 metre long ladder is leaning against the wall, just touching the cube.

 

Image
A unit cube resting against a wall and the floor. A ladder is placed so that it is on the floor, touching the edge of the cube which is opposite the edge touching both the floor and wall, and the ladder is also touching the wall.



How high is the top of the ladder above the ground?