Question

Sharon is decreasing the size of a diagram of a leaf that is 30 centimeters long by 10 centimeters wide, if the reduced diagram is 4 centimeters wide how long will it be?

Answer 1

$x-length\\\\From\ proportion:\\\\\frac{30}{10}=\frac{x}{4}\\\\10x=120\ \ \ \ \ \ |:10\\\\x=12\\\\It\ will\ be\ 12\ cm\ long$

Answer 2

Answer:

12 cm

Step-by-step explanation:

This is a proportionality/similarity problem.

10 cm turned to 4 cm. So by how much has it decreased? In other words, 10 multiplied by WHAT is 4?

$10*x=4\\x=\frac{4}{10}\\x=0.4$

0.4 is also known as the scale factor from the large diagram to the small diagram.

So how much would 30 cm become? It would be 30 multiplied by the scale factor, which is 0.4.

$30*0.4=12$

Hence, the length of the reduced diagram would be 12 cm.