ΔABC undergoes a dilation by a scale factor. Using the coordinates of ΔABC and ΔA'B'C', prove that the triangles are similar by AA.

ΔABC undergoes a dilation by a scale factor Using the coordinates of ΔABC and ΔABC prove that the triangles are similar by AA class=

Respuesta :

Given:

ΔABC undergoes a dilation by a scale factor and comes as ΔA'B'C'.

To show that both the triangles are similar.

Formula

  • By the condition of similarity we get,

If two triangles have three pairs of sides in the same ratio, then the triangles are similar.

  • By Pythagoras theorem we get,

[tex]Hypotenuse^2 = Base^2+Height^2[/tex]

Now,

In ΔABC,

AB = 18 unit

BC = 10 unit

So, [tex]AC^2 = AB^2+BC^2[/tex]

or, [tex]AC^2 = 18^2+10^2[/tex]

or, [tex]AC = \sqrt{424}[/tex]

Again,

In ΔA'B'C'

A'B' = 9 unit

B'C' = 5 unit

So, [tex]A'C' ^2 = A'B'^2+B'C'^2[/tex]

or, [tex]A'C'^2 = 9^2+5^2[/tex]

or, [tex]A'C' = \sqrt{106}[/tex]

Now,

[tex]\frac{AB}{A'B'} = \frac{18}{9} = 2[/tex]

[tex]\frac{BC}{B'C'} = \frac{10}{5} = 2[/tex]

[tex]\frac{AC}{A'C'} = \frac{\sqrt{424} }{\sqrt{106} } = 2[/tex]

Hence,

All the ratios are equal.

Therefore, we can conclude that,

ΔABC and ΔA'B'C' are similar.