Segment and Angle Addition Review

The parts have to add up to equal the whole. This also means we could use the whole and subtract one of the parts to find the other part.

We can also use Segment Addition to set up equations that we can then solve. The equation would say _____ + _____ = whole, and the two parts would go in the blanks.

We can also use Segment Addition to solve for x and then find a specific measurement. Set up the equation as ____ + ____ = whole, solve for x, then SUBSTITUTE the value for x back into the indicated expression.

The smaller angles (the parts) have to add up to equal the whole angle. This also means that we could take the total for the whole angle and subtract one of the parts to find the other part.

To know what the parts and the whole are for angles, you need to know how angles are named.

We use THREE letters to name an angle, and the middle letter should be the vertex.

Notice how first you have to determine where the pieces of information go in the picture. Then you decide whether you add or subtract to get the answer.

Start by identifying which pieces of information go where in the picture. Then set up an equation that shows _____ + _____ = whole, where the two parts go in the blank and are set equal to the whole.

Sometimes we have to set up an equation to solve for x using Angle Addition; remember the equation should be set up as _____+_____=whole, with the parts going in the blanks. But then after we solve for x we can substitute it into an expression to find a specific angle measure.