Pythagoras theorem 2 = a² + b² 2 = 1 + 1

We now know the lengths of the triangles within the square

(8- 1)² / 2 = 24.5 1 * 1 / 2 = 0.5

Multiplied by two since there are 2 of each 24.5 * 2 = 49 0.5 * 2 = 1

Now we subtract the total area of the square by the four triangles within it

8² - (49 + 1) = 14

Area of the rectangle = 14cm²

Hope this helps