Respuesta :

Hi the answer is 10.

The left side went from 18 to 6. So it got scaled down by a factor of 1/3.

If the bottom side is originally 30. It will get scaled down to 10 because 30*1/3 = 10.

Answer
20 inches
When the instructions says a triangle is similar it means they are exactly the same unless otherwise specified
We need to find the ratio
The DE is 6 inches while AB is 18 inches
The ratio between DEC and ABC is 1:3
So if AC is 30 the Dc should be 10
Next we should subtract DC fromAC to find AD
30-10=20
The answers AD=20 inches
Hope it helps