Draw a rectangle on top of the large square.

The top side of this rectangle should be level with the top side of the small square. The base of the rectangle is the top side of the large square, 10cm long. The right side of this rectangle should be joined to the small square.

You will now see a large unshaded triangle that is 14cm by 16cm.

The combined height of the small and medium square = combined height of the rectangle and large square

Combined height of small and medium square = 10cm + 4cm = 14cm

So height of rectangle
= 14cm - side of large square
= 14cm - 10cm
= 4cm

Area of the whole figure now
= Area of the three squares + area of rectangle

= (10 x 10 + 6 x 6 + 8 x 8 + 4 x 10)cm²
= (100 + 36 + 64 + 40)cm²
= 240cm²

Shaded area
= total area of figure - area of small unshaded triangle - area of large unshaded triangle

= 240cm² - ½ x 14cm x 16cm - ½ x 8cm x 8cm

= 240cm² - 112cm² - 32cm²
= 96cm²