(4 Points) Here is a triangle
Angle PQR= 120°
PQ= 6 CM
QR= 9 CM Work out the length PR

Step-by-step explanation:

You know the lengths of two sides and the angle between them. Use the Law of Cosines to solve the triangle.

PR^2 = 6^2 + 9^2 - 2*6*9*cos(120°)

= 36 + 81 - 108(-0.5)

= 13

step-by-step explanation:

points a and b are equidistant from the desired line, so the line you find by using them will go through point r.

using points other than a and b will give the desired line only if they are equidistant from r. if they are randomly located, the perpendicular line you create will not necessarily go through point r, hence will not be a solution to the problem.