Alex is thinking of a doubles fact. the sum is greater of 7+7 but less then the sum of 8+9. what fact is alex thinking of?

8+8=16

This the answer because 16 is greater that 7+7, but less than 8+9 and 8+8 is a doubles fact. So the answer makes sense.

SAS congruency:

example---- figure attached.

ASA congruency:

What it says--- If any two angles and the included side are the same in both triangles, then the triangles are congruent.      

Information required---- two pair of congruent triangles and one corresponding sides.

example----figure attached.

AAS congruency:

What it says----if two angles and the non-included side one triangle are congruent to two angles and the non-included side of another triangle, then these two triangles are congruent.

Information Required----Two angles and a non-included side are congruent.

example---- figure attached.

HL congruency:

What it says---- When two right triangles have corresponding sides that are congruent , the triangles are congruent.

Information required---- two right triangles and the sides are congruent.

Example--- figure attached.