Which postulate/ theoream that proves congruent tiranlges could be used to prove that BAC DEC ?
You could use Angle Angle Side because ACB and DCE are vertical angles.
The trick, of course, is that you cannot use SSA since SSA(Side Side Angle) is not a valid theorem that proves congruent tirangles.
Which postulate/ theoream that proves congruent tiranlges could be used to prove that ABC FED? (Use both the stated given as well as the markings on the picture of the triangles)
The two triangles are congruent by SAS, the side angle side postulate. You'd need to use the addition property of equality to get one pair of the sides.
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