Question

What is the distance between the points (21, -30) and (3, 8)? If necessary, round your answer to two decimal places.

Answer 1

The formula of the distance between two points:

$A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\|AB|=\sqrt{(x_B-x_A)^2+(y_B-y_A)^2}$

We have:

$A(21;-30);\ B(3;\ 8)$

Substitute:

$|AB|=\sqrt{(8-(-30))^2+(3-21)^2}=\sqrt{38^2+(-18)^2}\\\\=\sqrt{1444+324}=\sqrt{1768}\approx42.05$

Answer: B. 42.05 units.