Answer:
Perimeter is 17.07
Step-by-step explanation:
We know that DF = EF = 5 cm, since D and E are the midpoints of AC and AB, both of which are 10 cm in length.
We need to use the Pythagorean theorem to get the length of DE.
[tex]DE = \sqrt{5^{2} +5^{2}}=\sqrt{50} = 7.07\\[/tex]
So the perimeter of DEF is 5 + 5 + 7.07 = 17.07
