Final answer:
In an acute triangle, the sum of the three angles is 180 degrees. To find y, subtract the sum of the other two known angles from 180 degrees. In this case, y is equal to 68 degrees.
Step-by-step explanation:
An acute triangle has three angles.
The sum of the angles in any triangle is always 180 degrees. So, to find the measure of angle y in the given acute triangle, we subtract the sum of the other two known angles (89° and 23°) from 180°:
y = 180° - (89° + 23°)
= 180° - 112°
= 68°.
Therefore, the measure of angle y in the given acute triangle is 68°.
Learn more about Angles in a triangle