Answer:
What??
Step-by-step explanation:
I know this doesn't really help but... Good luck on the test!! And also I'm pretty sure they have youtube vids on how to do this stuff. Well, anyway bye!!! Good luck!!!
It is a straight line of symmetry because if you have a paper A and you fold it, it will form a straight line, and that is also meaning a straight line of symmetry. If you fold it any other way, it will not be a line of symmetry.
Hope this helps you ;)
54 because the formula for the area of triangle is 1/2bh so you just substitute the b and h for 18 and 6