On a two-way or undivided highway, how should the three warning triangles be placed around a stopped vehicle?

49 CFR 392.22(b)(1); AAMVA CDL Manual Section 2.5.2, pp.2-12 to 2-13, Fig 2.9

A two-way highway has traffic in both directions, so warning devices have to protect the vehicle from both sides, not just one. Splitting the triangles between the front and the rear, with one close to the vehicle itself, is what the federal placement rule and the manual both require. This exact placement pattern shows up directly on the knowledge test.