### Tennis

A tennis ball is served from directly above the baseline (assume the ball travels in a straight line). What is the minimum height that the ball can be hit at to ensure it lands in the service area?

### Soma - So Good

Can you mentally fit the 7 SOMA pieces together to make a cube? Can you do it in more than one way?

### Nine Colours

Can you use small coloured cubes to make a 3 by 3 by 3 cube so that each face of the bigger cube contains one of each colour?

# Oblique Projection

### Why do this problem?

Representing 3D objects in two dimensions on paper is a vital skill in the Design Technology curriculum, as well as an aspect of Shape and Space in the Maths curriculum.  This problem is part of a set of problems which will help students to understand why there are different ways to represent a 3D object in two dimensions, and what maths lies behind each method.

The article 3D Drawing was written to support these problems.

### Key questions

What are the advantages of this method of 3D drawing?  What are the disadvantages?

What features of the object are retained in the drawing, which are not?

### Possible extension

Oblique Projection is probably the easiest for students to understand.  Those who find it straight-forward should be encouraged to tackle the other problems in this set (linked from 3D Drawing) and to compare the various methods.

### Possible support

Students who find it difficult to draw the multi-link structure shown in the problem could be given simpler multi-link structures to draw, helping them to build up to drawing more complex ones.