7) The triangles are not congruent. The triangle on the left shows SAS while the triangle on the right shows SSA. The order matters due to how the angle is placed. The triangles may be congruent, but we don't have enough information to say yes or no. So we just go with "not congruent".
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8) The triangles are congruent by the HL theorem. HL stands for hypotenuse leg. This only works for right triangles. The sides with triple tickmarks are the hypotenuse, and the double tickmarked sides are one of the legs.
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9) The triangles are congruent by the SSS postulate. SSS stands for side side side. We have three pairs of corresponding sides that are same length. The tickmarks tell us how the sides pair up.
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10) The triangles are not congruent. We simply don't have enough info. We need another pair of sides to be congruent (to use SSS) or some information about the angles (so we can use SAS or ASA or AAS) to be able to know the triangles are congruent. This is similar to problem 7 above.