HEY THERE !!
TO PROVE :- 2DE = DF
It is given that E is the mid point of line DF. So indirectly DE = DF { by the defination of mid point} .....1️⃣
Now we can write that DE + EF = DF { by substitution} .........2️⃣
So according to 1️⃣ and 2️⃣we can write that
DE + DE = DF
=> 2DE = DF
HENCE PROVED
