Rectangle a has side lengths of 6 cm and 3.5 cm. the side lengths of rectangle b are proportional to the side lengths of rectangle a. what could be the side lengths of rectangle b? a. 3cm and 1.75cm b. 5cm and 2.5cm c.7 cm and 7cm d. 12cm and 5 cm e. 5.25cm and 9cm

To determine whether or not these are proportional, take the two side lengths that are given and create a ratio. 6cm:3.5cm. I suggest writing this in fraction form to better see the equivalency. If you divide both 6cm and 3.5 cm by 2, you create an equivalent ratio of 3 cm:1.75cm. This is answer A. There is another correct answer too! If you take 6cm:3.5cm and multiple both by 1.5, it will create an equivalent ratio of 9cm:5.25 cm (answer choice E), just in a different order.