Question

dorothys bookmark is shown in the image below. what is the area of dorothy’s bookmark? 1 cm 9 cm 11 cm 5 cm the area of dorothys bookmark is square cm.

Explanation:

Step1: Divide the bookmark into a rectangle and a trapezoid

The rectangle has dimensions \(9\mathrm{cm}\times5\mathrm{cm}\). The trapezoid has parallel sides \(9\mathrm{cm}\) and \(11\mathrm{cm}\), and height \(1\mathrm{cm}\).

Step2: Calculate the area of the rectangle

The area of a rectangle \(A_{1}=l\times w\), where \(l = 9\mathrm{cm}\) and \(w = 5\mathrm{cm}\). So \(A_{1}=9\times5 = 45\mathrm{cm}^{2}\).

Step3: Calculate the area of the trapezoid

The area of a trapezoid \(A_{2}=\frac{(a + b)h}{2}\), where \(a = 9\mathrm{cm}\), \(b = 11\mathrm{cm}\), and \(h = 1\mathrm{cm}\). So \(A_{2}=\frac{(9 + 11)\times1}{2}=\frac{20\times1}{2}=10\mathrm{cm}^{2}\).

Step4: Calculate the total area

The total area \(A=A_{1}+A_{2}\). So \(A = 45+10=55\mathrm{cm}^{2}\).

Answer:

\(55\)