The perimeter of an equilateral triangle is 18 cm. Find the perimeter of a rectangle whose length is equal

The perimeter of an equilateral triangle is 18 cm. Find the perimeter of a rectangle whose length is equal to the side of this triangle and the width is 2 times less than the length.

An equilateral triangle is a triangle in which all three sides are equal to each other, that is, equal to a.

The perimeter of a triangle is the sum of the lengths of all its sides.

Then the perimeter of an equilateral triangle (Ptr) will be equal to:

Ptr = a + a + a = 3a.

Knowing the perimeter of the triangle, you can calculate the length of the sides:

a = Ptr: 3;

a = 18: 3 = 6 cm.

Let’s calculate the perimeter of the rectangle.

Its length is equal to the side of a given triangle, that is, 6 cm.

Find the width of the rectangle:

6: 2 = 3 cm.

Perimeter of the rectangle Ppr:

Ppr = 2 * 6 + 2 * 3 = 18 cm.

Answer: 18 cm.