The length of side DE is 3cm
Parallel line
Since the line AC is equivalent to DE, hence AC = DE
To get the length of DE, we will need to get the length oF AC using the Pythagoras theorem:
Given the following parameters
Hypotenuse = 5
Opposite = 4
Required
Adjacent side
Substitute the given parameters into the formula of Pythagoras theorem.
AC² = 5² - 4²
AC² = 25 - 16
AC² = 9
AC = 3
Hence the length of side DE is 3cm
Learn more on Pythagoras theorem here: https://brainly.com/question/12306722
