Answer:
a) CD = 8 cm
b) Perimeter of EBCD is 19.8 centimeters
Step-by-step explanation:
For this question, you can assume that ΔABE and ΔACD are similar. That's proven by BE ║ CD, but that's not directly relevant to the question so I won't explain it unless you would like me to.
In 2 similar triangles, all corresponding angles are congruent and all corresponding sides have the same scale factor.
For example, in ΔABC and ΔXYZ:
[tex]\frac{AB}{XY} =\frac{AC}{XZ} =\frac{BC}{YZ}[/tex]
Using those relationships, you can solve for any side in one triangle given the corresponding side in the other triangle.
A)
In the given triangles ΔABE and ΔACD, CD corresponds to BE, so:
[tex]\frac{CD}{BE} =\frac{AD}{AE}[/tex]
where AD is just 6 + 4 = 10.
[tex]\frac{CD}{4.8} =\frac{10}{6} \\\\\frac{CD}{4.8} =1.6667\\\\CD=8[/tex]
CD = 8cm
B)
Doing the same thing as above, now find the length of AC:
[tex]\frac{AC}{AB} =\frac{AD}{AE} \\\\\frac{AC}{4.5} =\frac{10}{6}\\\\\frac{AC}{4.5} =1.6667\\\\AC=7.5[/tex]
Now, to find BC:
[tex]BC=AC-AB\\BC=7.5-4.5\\BC=3[/tex]
Finally, add up the sides to find the perimeter of EBCD:
[tex]4.8+3+8+4\\19.8[/tex]
Perimeter of EBCD is 19.8 centimeters