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If three central angles measures 65, 87, and 112, find the measure of the fourth central angle.
The best and most obvious way is to use a protractor. Other than that, there is no obvious and easy way.
You find central angle by using proportions. Part/Whole = x/360 Then, cross multiply and divide.
A rectangle is a quadrilateral (four sided shape) with four right angles. Therefore, the measure of every angle is 90 deg.