A placard indicating hazardous materials is shaped like a: Before you start the test, please answer the question below regarding your insurance status. Without insurance you will not be able to drive in Ohio Do you currently have car insurance? Yes I have insurance. Great, you're all set! Click here if you still want to compare rates. No, I need insurance. Click here to compare rates from our insurance partner. Question A placard indicating hazardous materials is shaped like a: Answers Diamond. Triangle. Circle. Explanation Hazardous materials warning placards are diamond-shaped. This questions appears in the following tests: Alabama HazMat Arizona HazMat Arkansas HazMat Delaware HazMat Delaware HazMat Idaho HazMat Iowa HazMat Louisiana HazMat Maryland Tank Missouri HazMat Nevada HazMat New Mexico HazMat Ohio HazMat Rhode Island HazMat South Carolina HazMat Utah HazMat Washington HazMat Wisconsin HazMat