E area of a trapezium is given by A=12(a+b)h. A new backyard deck in the shape of the trapezium shown is being designed. PIC Currently the dimensions are set such that a=12 m and h=10 m. What range of b values is required for an area of at most 110 m2? Rearrange the area formula to make b the subject. Use your answer to part b to find the length b m required to give an area of 100 m2. Rearrange the area formula to make h the subject. If b is set as 8 m, what does the width of the deck (h m) need to be reduced to for an area of 80 m2?