Problem 91 of 7
Prove the isosceles base angles theorem for triangle FGH with FG=FH.
Using a hint is okay. It just tells the trainer to give you a little more review.
Hidden until you reveal it.
use triangle congruence or symmetry.
Hidden until you reveal it.
Proof must use triangle congruence, symmetry, or an auxiliary segment from the vertex.
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Your answer is equivalent to the expected form.
Walkthrough
Full solution stays hidden until you ask for it.
1. Construct an auxiliary segment from the vertex to the base.
2. Prove the two smaller triangles are congruent or symmetric.
3. Use corresponding parts to conclude base angles are congruent.
Use the worked steps, then substitute the final answer back into the original relationship to confirm it satisfies the prompt.
Proof that assumes base angles are equal without justification.