Question

Peter (P) and Jamie(J) have computer factories that are 132 miles apart. They both ship their completed parts to Diane (D). Diane is 72 miles from Peter and 84 miles from Jamie. Using the points D,J,and P to form a triangle, find m<PDJ to the nearest tenth of a degree.

Answer 1

Given ΔPDJ,
PJ=132 miles
PD=72 miles
DJ=84 miles

Triangle (angles) can be solved using the cosine rule, since all sides are known.

Let ∠PDJ = θ

Then
cos(θ) = (PD^sup2;+DJ²-PJ²)/(2PD*DJ)

Can you take it from here?

Answer 2

115.4