Answer: The scale factor of triangle CAT to triangle MUD is the ratio of the corresponding side lengths of the two triangles. In this case, we are told that the sides of triangle CAT are 9, 18, and 21 units long, and the sides of triangle MUD are 3, 6, and 7 units long.
To find the scale factor, we divide the length of each side of triangle CAT by the length of the corresponding side of triangle MUD:
Scale factor = (9/3), (18/6), (21/7) =3,3,3
So the scale factor of triangle CAT to triangle MUD is 3. This means that triangle CAT is 3 times larger than triangle MUD.
It's worth noting that the scale factor is the same for all three sides, this means that the two triangles are similar.
Explanation: