Selective SelectiveServiceSystem

(Three sides correspond to the coincidence of two equal triangles)

Step 2: Dilemma

American Statistical Society; usa standards institute

(Two corners and their clamping edges correspond to the coincidence of two triangles)

3. Corners and edges

Scandinavian airlines

(Two sides and their included angles correspond to the combination of two equal triangles)

4. Corner edge

American Statistical Society; usa standards institute

(The opposite sides of two angles and one angle correspond to the congruence of two equal triangles)

5. Right angles and hypotenuses

Baisheng

(Two right-angled triangles with equal right angles and hypotenuses are congruent)

The corresponding equations mean, for example, ABC and DEF,

AB and DE are corresponding edges, AB = DEBC and EF are corresponding edges, BC = EFAC and DF are corresponding edges, and AC=DF.

Angle a and angle d are corresponding angles, and angle A= angle d;

Angle b and angle e are corresponding angles, and angle B= angle e;

Angle c and angle f are corresponding angles, and angle C= angle f.

These correspondences can be written in alphabetical order from triangle XXX and triangle yyy given in the title.