This is very important idea/rule in angle geometry. It is very similar concept to angles on a straight line. The idea is that in a full spin you have 360degrees (remember in tests to use the symbol).
The way we find the solution is to take all the other numbers off (subtraction) 360 degrees.
In this example you would type into your calculator
360 - 110 - 75 - 50 - 63 = 62 degrees.
In NCEA you get 'achieve' grades for getting the numbers right. You have to have the degree symbol. You get a 'merit' grade if you have the right reason. E.g.
Achieve to say...
360 - 90 - 105 - 25 = 140 degrees.
Merit to say...
360 - 90 - 105 - 25 = 140 degrees because angles at a point add to 360 degrees.
The work for this is Exercise 14.10 on page 221. Again do answers only for all but five problems (where you can do a sketch). The sketch is for you future revision.
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