A triangle has two sides and each of them is 2/7 of its perimeter. The third side is 21 cm.

univerkov | July 13, 2021 | education

A triangle has two sides and each of them is 2/7 of its perimeter. The third side is 21 cm. Find the perimeter of this triangle.

Since the two sides are 2/7 of the perimeter each of them, the sum of these two sides will be 2/7 + 2/7 = 4/7 from the perimeter of the triangle.

Then the third side is 7/7 – 4/7 = 3/7 of the perimeter and is equal to 21 cm.

Let’s make a proportion and solve it.

3/7 – 21 cm.

7/7 – X cm.

X = 21 * 1 / (3/7).

X = 21 * 7/3 = 49 cm.

Answer: The perimeter of the triangle is 49 cm.

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.