Not as hard as it seems
We have a rectangle with an area of Width * Height = 34 * 14 = 476 units^2 (1)
Note...that at the two ends, we have two semi-circles with a radiuses of 7
So...the total area of these combined will actually be a circle with a radius of 7 = pi * 7^2 = 49pi units^2 (2)
So the shaded area = (1) - (2) = 476 - 49pi ≈ 322.1 units^2