Since the angle measures in a triangle are positive, this means that the measure of both ∠ Y and ∠ Z are less that 23. We want to write an inequality for the measure of ∠ Z using the notation z=m∠ Z, so the following is a possible answer.
z<23
Extra
Interior and Exterior of an Angle
We know that an angle divides the plane into two parts:
the region between the sides, or interior of the angle, and
the region outside the sides, or exterior of the angle.
These regions can be examined in the following graph.
Notice that the interior of an angle is the region for which the angle measure is less than 180^(∘).
