The arrow reaches a height of 31.888m or 32m with significant figures.
We know that the initial velocity is 25m/s. We also know that the final velocity is 0m/s. This is because at the maximum height of an object thrown straight up, the object stops moving for a split second before coming back down. The acceleration of the object is -9.8m/s^2 because of gravity. The negative is important because gravity is in the negative y direction, and the ball was thrown in the positive y direction. See the picture for the kinematic equation and how to solve for the height.