The perimeters of two squares are 40 cm and 28 cm. Find the perimeter of a third square whose area is equal to the difference of the areas of the two squares .  Choose one:  A) 22 cm  B) 28.4 cm  C) 26 cm  D) 28 cm  E) 29 cm
Explanation:   We know perimeter of square = 4(side)   So Side of first square = 40/4= 
<gadget id="calculator">40/4</gadget>
<output>10</output>
10 cm   Side of second square= 28/4= 
<gadget id="calculator">28/4</gadget>
<output>7</output>
7 cm   Area of third Square= 10*10 - 7*7= 
<gadget id="calculator">10*10 - 7*7</gadget>
<output>51</output>
51 cm   So side of third square= 7.1 [because area of square = side*side]   Perimeter = 4*Side = 4*7.1= 
<gadget id="calculator">4*7.1</gadget>
<output>28.4</output>
28.4 cm   Answer: Option 28.4 cm
<result>B</result>
The perimeters of two squares are 40 cm and 28 cm. Find the perimeter of a third square whose area is equal to the difference of the areas of the two squares .