Chapter 11, Problem 6STP

To determine

To find: The perimeter of the larger rectangle.

Answer to Problem 6STP

The perimeter of the larger rectangle is $35$ millimeters.

Explanation of Solution

Given information:$$

Two similar rectangles with the scale factor $3:5$ .

Perimeter of the smaller rectangle is $21$ millimeters.

Finding the perimeter of the larger rectangle,

  $\begin{array}{c}\frac{21}{3}=\frac{x}{5}\to \text{by using proportional relationship}\\ \frac{21\times 5}{3}=x\\ x=\frac{105}{3}\\ x=35\end{array}$

The perimeter of the larger rectangle is $35$ millimeters.