The figure is an obtuse triangle. If we identify 4 as the base of the triangle, then the height extends from the base to meet vertex opposite the base at a 90° angle. The height of the triangle is outside the triangle itself. In this case, the height is represented by x.
Use area of triangle to find the height (x)
1/2 × b × h = area
1/2 × 4 × x = 16
2x = 16
x = 16/2
x = 8
The value of x is 8