# The ratio of the lengths of the sides of the rectangle is 4: 5. Find the area of this rectangle if the length of the smaller side is 12cm.

December 30, 2020 | education

| Let’s make a proportion according to the problem statement. Let x be the length of the larger side, then 4: 5 = 12: x. Let’s apply the main property of proportion: the product of the extreme terms is equal to the product of the middle terms of the proportion

4: 5 = 12: x

4 * x = 12 * 5

4x = 60

x = 60/4

x = 15

This means that the large side is 15 cm. The area of the rectangle is equal to the product of its adjacent sides (length and width). So,

S = 12 * 15 = 180 cm ^ 2

Answer: 180 cm ^ 2

One of the components of a person's success in our time is receiving modern high-quality education, mastering the knowledge, skills and abilities necessary for life in society. A person today needs to study almost all his life, mastering everything new and new, acquiring the necessary professional qualities.