If you know the area and the base of a triangle, how can you find the height? Divide the area of the triangle by the base, and divide the result by 2. Multiply the area of the triangle by the base, and divide the result by 2 00:00 Divide the area of the triangle by the base, and multiply the result by 2 00:00 Multiply the area of the triangle by the base, and multiply the result by 2.