If the effects of heat and friction are ignored, the amount of work output is always <u>same as</u> the amount of work input, even when using a simple machine.
Simple machines make work easier, but they do not decrease the amount of work one has to do.
A simple machine can change the amount of force applied to an object, and the distance over which the force is applied.
<em><u>The efficiency of simple machines is the ratio of work output to work input as a percentage. However, the efficiency is never 100% due to heat and friction. Therefore, if heat and friction then the efficiency would be 100% which means that the work input is equal to the work output.</u></em>
There are two 45 degree angles and since a triangles sides ALWAYS add up to 180 we know the the other side has to be 90 degrees because 45+45+90=180. And we know that every triangle has three sides because "tri" means three.