In the figure, ABCD and EFGF are rectangle. ABCD and EFGH are similar.(a) If the length of AB is a cm, try to use a to Indicate the length of EF(b) Find the ratio of the areas of ABCD and EFGH.(English isn't my native language. Please correct me if I have any grammatical mistakes.)

In the figure ABCD and EFGF are rectangle ABCD and EFGH are similara If the length of AB is a cm try to use a to Indicate the length of EFb Find the ratio of th class=

Respuesta :

Given:

BC = 3 cm, FG = 4 cm

Required: bLength of EF and ratio of areas

Explanation:

(a) Since the rectangles ABCD and EFGH are similar, the correponding angles are proportional. Hence

[tex]\frac{AB}{EF}=\frac{BC}{FG}[/tex]

Plug the given values.

[tex]\frac{AB}{EF}=\frac{3}{4}[/tex]

If AB = a cm, then

[tex]\begin{gathered} \frac{a}{EF}=\frac{3}{4} \\ EF=\frac{4a}{3} \end{gathered}[/tex]

(b) Ara of ABCD

[tex]\begin{gathered} =\text{ Length}\times\text{ Width} \\ =3a\text{ cm}^2 \end{gathered}[/tex]

Area of EFGH

[tex]\begin{gathered} =\text{ Length}\times\text{ Width} \\ =4\times\frac{4a}{3} \\ =\frac{16a}{3}\text{ cm}^2 \end{gathered}[/tex]

Ratio of areas

[tex]\begin{gathered} =3a:\frac{16a}{3} \\ =9:16 \end{gathered}[/tex]

Final Answer: The ratio of areas of ABCD to EFGH is 916.