The formula for a trapezoid is A=0.5h(a+b) where a and b represent the two bases. If you look at the trapezoid sideways you see two bases, 20 and 16, and a height of 24. We will plug this into the equation.
Given that the interest rate is 10% which can be represented by 1.10t, the quarterly interested rate will be represented as follows: annual rate=10% quarterly rate=10/4=2.5%=0.025 given time t, this will be represented as : (1+0.025)t =1.025t