Points A (4: 5) and B (0: -1) lie on a circle. Calculate the length of the diameter AB

We know the coordinates of points A (4; 5) and B (0; -1), and we also know that it lies on a circle. To calculate the diameter of a circle, we must find the distance between the points lying on the circle, and in our case these are points A and B.

It remains for us to recall the formula for calculating the distance and apply it:

d = √ ((xa – xb) ^ 2 + (ya – yb) ^ 2).

We write out the coordinates of the points as follows:

xa = 4, xb = 0, ya = 5, yb = -1.

Substitute the values and calculate:

d = √ ((4 – 0) ^ 2 + (5 – (-1)) ^ 2) = √ (4 ^ 2 + 6 ^ 2 = √52 = 2√13.