Explanation:
Soln
From the above diagram
Height = h = 4cm
Let a&b = upward and downward lengths respectively.
That is:
a = 13cm
b = 16cm
recall that the formula used mathematically in solving/calculating the area of a trapezium is
Area = 1/2×(a+b)×h
Area = 1/2×(13+16)×4
Area = 1/2×(29)×4
Area = (29)×2
Area = 58cm²