The triangle is actually a right triangle. In step 2, Chelsea incorrectly substituted the values into the Pythagorean theorem. The triangle is not a right triangle, but in step 2 Chelsea incorrectly substituted the values into the Pythagorean theorem. The triangle is actually a right triangle. In step 3, Chelsea incorrectly rewrote the expression on the left side of the equation. The triangle is not a right triangle, but in step 3, Chelsea incorrectly rewrote the expression on the left side of the equation.