Aria unui dreotunghi este de 405 m2, iar latimea este de 15m. Calculeaza aria unui patrat care are latura egala cu un sfert din perimetrul dreptunghiului.

The area would be 441 m².

We first find the length of the given rectangle. We know area is length times width, that the area is 405 and the width is 15; this gives us:

405 = 15L

Divide both sides by 15:

405/15 = 15L/15

27 = L

Calculate the perimeter of the rectangle:

P = 2L + 2w = 2 (27) + 2 (15) = 84 m

The side of the square is 1/4 the perimeter of the rectangle we just found:

1/4 (84) = 21 m

The area of a square is equal to its side length squared:

A = s² = 21² = 441 m²