The formula for finding the area of a triangle is 1/2 base * height = area. In this case, we know the area and the base. Let's say the variable h represents height. We fill in the area and base with our known values to get 1/2 (30) * h = 450. Then, we solve. Half of 30 is 15, so 15h is equivalent to 450. Then, divide both sides by 15 to get h is equivalent to 30. To double check, fill in the base and area, and the newly found height. If the values make the equation make sense, the height is right. 1/2 (30) * 30 = 450. 15 * 30 is 450, so the height is 30 inches.