The original expression evaluates to 54.4 as shown in the first working.
_____ For some reason, 3.4 got transcribed to be 1.7 in the 3rd line of the second working. There is no math operation in the expression that requires 3.4 to be divided by 2.
for 2a, use the theorems of geometry and such to look at the area of the square as 16 squares total, then use the lengths and Sim/cos rule for the triangular area, then subtract and you have you shaded area.
