3D Drawings

As the name suggestions, $3$3D drawings have three dimensions.  They have a length, width and height, although sometimes the words breadth and depth are used as well.  

In this $2$2D drawing of a rectangle I don't need to mark on all the measurements for all $4$4 sides because we can tell from the markings on the diagram that the side marked with an $a$a, will be of length $8$8cm.  

Similarly in 3D drawings there is no need to mark on every dimension, just enough dimensions to be able to determine all relevent dimensions.  

Here is an example of what I mean.

Examples

Question 1

Determine the dimensions indicated by $A$A and $B$B on the diagram.

The total width is $8$8cm, and we can see widths of $2$2cm and $4$4cm This means that A must be $2$2cm.  

The total length is $15$15cm, and we can see sub-lengths of $5$5cm and $5$5cm already.  This means that $B$B must also be $5$5cm in length.  

As you can see the key to solving these problems is to identify all the lengths that are relevent - and don't be afraid to draw on the diagrams it actually can be a big help!

QUESTION 2