The perimeter of an equilateral triangle is 12 cm 6 mm. The length of the side of the triangle is equal

The perimeter of an equilateral triangle is 12 cm 6 mm. The length of the side of the triangle is equal to the width of the rectangle. what is the length of the rectangle if the area is 21 cm2

Let’s convert millimeters to centimeters:

12 cm 6 mm = 12.6 mm.

In an equilateral triangle, all sides are equal. Therefore, one side of it is equal to:

a = P / 3, where P is the perimeter of the triangle.

Find the side of the triangle from the problem:

a = 12.6 / 3 = 4.2 cm.

This means that the width of the rectangle is also 4.2 centimeters. The area of the rectangle is:

S = ab, where a is the width of the rectangle, b is the length of the rectangle.

From this formula, we express the width of the rectangle:

b = S / a.

Let’s find the given length:

b = 21 / 4.2 = 210/42 = 5 cm.

Answer: The length of the rectangle is 5 centimeters.