We cannot take half of 9 people. The even numbers, then, are the numbers divisible by 2: 2, 4, 6, 8, and so on. The odd numbers are 1, 3, 5, 7, and so on. If you do not know half of some even number, you can find it by decomposing it mentally into two even numbers whose half you do know.
To draw a shape, line or angle accurately using a compass and straightedge (ruler). Sometimes you are also allowed to use a protractor and triangle.
Dictionary of Construction. 1. A stated requirement of the contract documents whereby a specified sum of money is incorporated, or allowed, into the contract sum in order to sustain the cost of a stipulated material, assembly, piece of equipment, or other part of a construction contract.