Answer: 3/4
16 squares in total, with 4 fully shaded hence remaining (unshaded) = 12/16 = 3/4 (after simplifying)
Concept is a bit like jigsaw puzzle. Try to fit the partially shaded parts to form one shaded square

Thank you

Trying to fit the shaded parts together like a jigsaw is not the best method to answering this question because sometimes it is difficult to judge if the area fits. The best way the is to calculate the area of the two unshaded triangles. The big triangle is 0.5x4x4 units^2 and the small triangle is 0.5x2x4 units^2. Then sum the two areas and divide by the area of the whole square 4x4 units^2.

Alternatively,

Let length of 1 small square be 1 unit.

Area of shaded triangle = ½ x base x height
= ½ x 2 units x 4 units
= 4 units²

Area of big square
= 4 units x 4 units
= 16 units²

Fraction that is shaded
= 4 units² ÷ 16 units²
= ¼

Fraction that is unshaded
= 1 - ¼ = ¾