Answer:
Perimeter of Triangle: 

Step-by-step explanation:
The perimeter is the sum of all of the sides of the triangle.
Hence, the perimeter 
Since the perimeter is 90,
.
Subtract 15 from both sides:


Divide both sides by 6:


Answer:
B. AAS Congruence Theorem
Step-by-step explanation:
Previous steps showed congruence of a side of the designated triangle, and two angles that do not bracket that side. In short form, you have shown congruence of ...
Angle - Angle - Side
so the AAS congruence theorem applies.
The answer is 2.5 percent