bab0409
contestada

Two rectangles are similar. If the height of the first rectangle is 3 inches, and the height of the second rectangle is 9 inches, how much longer is the second rectangle's perimeter? 3 times as long 6 times as long 9 times as long 6 inches longer

Respuesta :

3 times as long .....hope this helps

Answer:

Option a.

Step-by-step explanation:

Two rectangles are similar. Height of one rectangle is 3 inches and height of second rectangle is 9 inches.

Let width of rectangles are x inches and y inches.

Then width of the second rectangle will be in the same ratio as of their heights.

[tex]\frac{x}{y} =\frac{3}{9}[/tex]

[tex]\frac{x}{y} =\frac{1}{3}[/tex] ⇒ x = [tex]\frac{y}{3}[/tex]

Now perimeter of first rectangle P₁ = 3 + 3 + x + x  = 2x + 6

Perimeter of second rectangle P₂ = 9 + 9 + y + y = 18 + 2y

Ratio of P₁ and P₂ = [tex]\frac{2x+6}{18+2y}[/tex]

                             = [tex]\frac{2(\frac{y}{3})+6}{18+2y}[/tex]   [as [tex]x=\frac{y}{3}[/tex]]

                            = [tex]\frac{\frac{(2y+18)}{3} }{(18+2y)}[/tex]

                            = [tex]\frac{2y+18}{3(18+2y)}[/tex]

Ratio of P₁ and P₂ = ([tex]\frac{1}{3}[/tex]) ⇒ P₂ = 3P₁

Therefore, Option a is the answer.