Answer:
5
Step-by-step explanation:
One is given that the scale factor to get from triangle (ABC) to triangle (DEF) is ([tex]\frac{1}{2}[/tex]). This essentially means that one has to multiply the sides of (ABC) by ([tex]\frac{1}{2}[/tex]) to get the corresponding side in the triangle (DEF).
As one can see, side (AB) corresponds to side (DE), therefore, multiply the length of (AB) by ([tex]\frac{1}{2}[/tex]) to get the side of (DE).
AB * [tex]\frac{1}{2}[/tex] = DE
Substitute,
[tex]10*\frac{1}{2}=DE[/tex]
Simplify,
[tex]5=DE[/tex]
([tex]ED[/tex]) is another way of naming segment ([tex]DE[/tex]) this is explicitly clear from the diagram of the tirnagles.
