What is the formula for the area of a triangle?

The formula for the area of a triangle is A = (1/2)bh, where A represents the area, b is the base of the triangle, and h is the height measured from the base to the opposite vertex.

This formula comes from the understanding that the area of a triangle is essentially half the area of a rectangle. When you take a rectangle's area, you multiply the base by the height (A = bh). Since a triangle occupies half of that rectangle when split diagonally, you factor in the 1/2 to determine the area of the triangle.

The other formulas presented do not apply to the area of a triangle: A = bh would be correct for a rectangle, A = lwh is for the volume of a rectangular prism, and A = 2bh does not represent the area of a triangle but would incorrectly suggest that the area is double that of a triangle's area.