Answer:
The height is 10.
Explanation:
Since the trapezoid is 2 triangles plus a square, we can split it into a rectangle (the two triangles put together) and the square. Let's call the height "x". The trapezoid's area becomes 8x [the square]+2x[the traiangle]. But wait! It states that the area is 70m, so the expression becomes the equation 10x=70m, which is x=10. Therefore, the height is 10.