Area of a triangle is given by the formula a=1/2bh . The area of the triangle shown to the right is 88 sq. units. Find its base and height. A triangle with a horizontal side labeled 2 x + 10 has a dashed line labeled x + 2 that extends from its top vertex to the horizontal side. The line and horizontal side are perpendicular. x plus 2 2 x plus 10 Read the problem carefully. To find the base and height, first identify the base and the height from the given figure. For the given triangle, the base is nothing and the height is nothing.