The vertices of are d(7, 3), e(4, -3), and f(10, -3). write a proof to prove that is isosceles.

The vertices of are D(7, 3), E(4, -3), and F(10, -3)

Prove tat DE = DF
Length of a segment = √[(x₂ - x₁) +(y₂ -y₁)]

DE = √([4-7)² + (-3 -3)²] = √45 = 3√5
DF = √[(10-7)² +(-3 -3)²] = √45 b= 3√5
Hence DE = DF = 3√5 and DEF is  ISOSCELES 

Not so sure about this one sorry.