HL theorem is a theorem to prove the congruence of two right triangles. It is proved that the right side and hypotenuse of two right triangles are equivalent.
The judging theorem is: if the hypotenuses of two right-angled triangles and a right-angled side are equal, then the congruence of these two right-angled triangles (abbreviated as HL) is a special judging method, which can be transformed into ASA, which is a case where SSA can be confirmed.
Extended data
To determine the congruence of two triangles, it is necessary to know that at least three of the six elements of the triangle and the triangle are equivalent.
1, corresponding to three sets of congruent "edges" of two triangles with equal sides, which is abbreviated as "SSS".
2. A triangle has two congruent "angles", and the included angles of the two sides are equal, which is called "SAS" for short.
3. The congruent "angles and angles" of two triangles with two angles and their clamping edges are called "ASA" for short.
4. The two congruent "corner edges" of a triangle with two angles and the opposite side of one angle are called "AAS" for short.
In the judgment of congruence, there are no AAA (Angle) and SSA (side angle, that is, two sides and their diagonals), and neither of them can uniquely determine the shape of a triangle.
For AAA, it is known that the two sets of corresponding angles of two triangles are equal, so the third angle can be 180 from the sum of the internal angles of the triangle. In fact, only two elements are equal, and the absence of elements is uncertain.
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