distance (2,3),(2,5)
The distance is the norm of the difference of the points: the square root of the sum of the squared coordinate differences
Let's evaluate: ‖(2, 5) -(2, 3)‖
ⅰ (2, 5) -(2, 3) = (2 -2, 5 -3)
‖(2 -2, 5 -3)‖
ⓘ Start from 2 and move back 2 on the number line, down to zero: 2 -2 = 0■Start from 5 and move back 3 on the number line: 5 -3 = 2
‖(0, 2)‖
ⅰ ‖(0, 2)‖ = 02 + 22
02 + 22
ⓘ Adding 0 changes nothing: 0 + 22 = 22■An integer power is a repeated product: 22 = 2×2 = 4
4
ⓘ The square root of a number is the positive number whose square is that number: 4 = 2; 22 = 4
▶Distance:   2