Finding solubility constants in a titration

Dec 2018
For a lab we are doing in class, we were given this data:

Mass of Potassium Hydrogen Phthalate: 0.10g (this was in the Erlenmeyer flask)
Volume of Water: 50 mL (also in the Erlenmeyer flask)
Volume of Calcium Hydroxide Used to Titrate: Trial 1-162.80mL, Trial 2-190mL, Trial 3-163.10 mL (substance in the burette)

We are required to find the Ksp value of the calcium hydroxide, but I have no idea how to approach this, given the data we have. If anyone has an idea, please let me know.