Question

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

A.38 units
B.42.05 units
C.33.47 units
D.56 units

Answer 1

The formula of the distance between two points:


`A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\|AB|=√((x_B-x_A)^2+(y_B-y_A)^2)`

We have:


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

Substitute:


`|AB|=√((8-(-30))^2+(3-21)^2)=√(38^2+(-18)^2)\\\\=√(1444+324)=√(1768)\approx42.05`

Answer: B. 42.05 units.