One angle in a linear pair is 70 degrees. What is the second angle.?

##110˚##

This is a pair of linear angles. Linear angles always form a line—that is, they form ##180˚##, or a straight angle.

Therefore, the angle in the linear pair with the ##70˚## angle must have a combined sum with the ##70˚## angle of ##180˚##.

We can write this as ##70˚+x˚=180˚##, where ##x˚## is the measurement of the other angle in the linear pair.

If we take the equation and subtract ##70˚## from both sides, we see that ##x˚=110˚##, which is the measure of the second angle.