In the diagram, DG ∥ EF , to prove that DEFG is an isosceles trapezoid Option (a) DE ≅ GF is CORRECT.
To prove that DEFG is an isosceles trapezoid we need to check the each options accordingly.
Given: An isosceles trapezoid DEFG where, DG ∥ EF.
What is an isosceles trapezoid?
An isosceles trapezoid is a trapezoid where the base angles is equal and therefore the left & right side lengths are also equal. Here in the isosceles trapezoid the non parallel sides are congruent.
According to the figure DEFG is an isosceles trapezoid where,
DG║ EF,
- DG and EF sides are parallel.
- DE and GF sides are non parallel sides.
Hence according to the above definition the trapezoid will be isosceles only if DE & GF are congruent.
= DE ≅ GF
Therefore,Option (a) DE ≅ GF is CORRECT.
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