PLEASE HELP!!!!

Mike says that if he doubles each dimension of any rectangular prism, the surface area also doubles. Is Mike correct? Give an example to support your answer.

Respuesta :

Answer:

Mike is not right

Step-by-step explanation:

we know that

If two figures are similar, then the ratio of its surface areas is equal to the scale factor squared

Let

z----> the scale factor

x----> surface area of the enlarged rectangular prism

y-----> surface area of the original rectangular prism

[tex]z^{2}=\frac{x}{y}[/tex]

so

In this problem we have

[tex]z=2[/tex]

substitute

[tex]2^{2}=\frac{x}{y}[/tex]

[tex]4=\frac{x}{y}[/tex]

[tex]x=4y[/tex]

so

The surface area of the enlarged rectangular prism is 4 times the surface area of the original rectangular prism

therefore

Mike is not right

Verify with an example

we have a rectangular prism

[tex]L=5\ m[/tex]

[tex]W=2\ m[/tex]

[tex]H=3\ m[/tex]

The surface area of the prism is equal to

[tex]SA=2(LW)+(2L+2W)H[/tex]

substitute the values

[tex]SA=2*(5*2)+(2*5+2*2)*3=62\ m^{2}[/tex]

If he doubles each dimension of any rectangular prism

then

the new dimensions will be

[tex]L=5*2=10\ m[/tex]

[tex]W=2*2=4\ m[/tex]

[tex]H=3*2=6\ m[/tex]

The new surface area will be

[tex]SA=2*(10*4)+(2*10+2*4)*6=248\ m^{2}[/tex]

[tex]248/62=4[/tex]

therefore

The surface area of the enlarged rectangular prism is 4 times the surface area of the original rectangular prism