Question

I could use some help to find out Tony’s mistake(s)

Answer 1

To find the shaded area you subtract the area of the triangle from the area of the rectangle:

`A_(shaded)=A_(rec\tan gle)-A_(triangle)`
`\begin{gathered} A_(shaded)=w\cdot l-(1)/(2)b\cdot h \\ \\ A_(shaded)=(5cm)(11cm)-(1)/(2)(5cm)(3cm) \end{gathered}`

Then, Tony's mistake was that he added the areas instead of subtract it.

The shaded are is:

`\begin{gathered} A_(shaded)=55cm^2-(15)/(2)cm^2 \\ \\ A_(shaded)=55cm^2-7.5cm^2 \\ \\ A_(shaded)=47.5cm^2 \end{gathered}`

Then, the shaded area is 47.5 square centimeters