Answer:
(see below)
Step-by-step explanation:
First, you know that the first statement given is Given.
Now that you have that, you want to concentrate on your goal, and that goal is to prove that ΔGHI is an isosceles. To do this, you need to prove that the two base angles or two adjacent sides are congruent.
To do this, you can prove ΔGHJ ≅ ΔIHJ first, then use CPCTC.
Because HJ is the perpendicular bisector of GI, GJ ≅ IJ. this will be under Definition of Perpendicular Bisectors because it's a line which cuts a line segment into two equal parts at 90°.
This also means that ∠GJI and ∠IJH are right angles under Definition of Perpendicular Bisectors. Do not combine the two statements.
To clarify everything, ∠GJI ≅ ∠IJH because "all right angles are congruent."
It's also clear that these two triangles share a side, so HJ ≅ HJ. This is the Reflexive Property of Congruence, stating that for any real number a, a ≅ a.
Now you can prove these two triangles congruent by the SAS Postulate.
Using CPCTC, corresponding parts of congruent triangles are congruent, GH ≅ HI.
Your last statement should be ΔGHI is an isosceles because of Definition of Isosceles Triangle. You also want to state the statement exactly as given as the question.
Your proof should look something like IMAGE.A.
