Please help me with this sum. I've recreated the diagram in Photoshop.

So I've already worked out that TQ is 10cm (using the right angled triangle PTQ). But how to work out the other sides? I'm totally lost.One corner of this cuboid has been sliced off along the plane QTU. WU = 4cm.

a.) Calculate the length of the three sides of the triangle QTU.