△ XYZ∼ △ DEF, YZ is 10 meters, XZ is 15 meters, and EF is 8 meters. What is DF?
Solution:
As, △ XYZ∼ △ DEF , so the ratio of sides of triangle is equal.
So, we have, [tex] \frac{XY}{DE} =\frac{YZ}{EF} =\frac{XZ}{DF} [/tex]
Using, [tex] \frac{YZ}{EF} =\frac{XZ}{DF} [/tex]
So, we get,[tex] \frac{10}{8} =\frac{15}{DF} [/tex]
Now, to solve for DF, we must simplify
Simplifying,[tex] \frac{10}{8} =\frac{5*2}{4*2}=\frac{15}{DF) [/tex]
[tex] \frac{5}{4} =\frac{15}{DF} [/tex]
To simplify, Let us multiply by 4*DF on both sides
[tex] \frac{5*4DF}{4} =\frac{15*4DF}{DF} [/tex]
[tex] \frac{5DF}{1} =\frac{15*4}{1} [/tex]
So, 5 DF=15*4=60
To solve for DF, let us divide by 5 on both sides
[tex] \frac{5}{5} DF=\frac{60}{5} [/tex]
[tex] \frac{1}{1} DF=\frac{12}{1} [/tex]
So, DF=12meters
