△ABC has vertices at A(−5,1), B(2,1), and C(6,4). Point D is located on AC¯¯¯¯¯¯¯¯ in such a way that BD¯¯¯¯¯¯¯¯⊥AC¯¯¯¯¯¯¯¯. The coordinates of point D are approximately (1.52,2.78).

Question

How many units is the perimeter of △ABC?

20.6 units

29.0 units

23.4 units

26.0 units

Answer 1

This is an exercise in brute force arithmetic!

Use the distance formula to calculate the length of AC and the length BC.

The length of AB is 7.

Add the lengths to get the answer.

The information about the perpendicular is of no use in obtaining the solution.