We know the vertical and horizontal measures of the triangle. We can use these measures as the legs in the Pythagorean Theorem.
a^2+ b^2=c^2 ⇒ 10^2+ 5^2=c^2
Finally, we can solve for the hypotenuse c. This is the distance between the points. Remember that distances are always non-negative, so we will only use the positive square root.