$157^\circ$, efficient walker.
Work Step by Step
Step 1. Using the given figure, we can identify the three sides as $5.78,3.0,2.9\ ft$ Step 2. The pace angle $\theta$ faces the longest side and using the Law of Cosines, we have $5.78^2=3.0^2+2.9^2-2(3.0)(2.9)cos\theta$ and $cos\theta\approx-0.9194$ Thus $\theta=acos(-0.9194)\approx157^\circ$ Step 3. The pace angle is large and close to $180^\circ$m, indicating that this dinosaur was an efficient walker without wasting its pace sideways.