Answer:
Distributive property says that:

Addition property of equality:
if x = y then x+z = y+z
Division property of equality:
if x = y then 
As per the statement:
Given the equation: 
Tyra solve this equation as shown below:
1.
[Distributive property]
2.
[Addition property of equality]
3.
{Division property of equality]
Therefore, the property Tyra used in line 1 was : Distributive Property.
Step-by-step explanation:
Pythagoras' theorem for the smallest one :


= 52
Pythagoras' theorem for the middle one :
=
+ 
Pythagoras' theorem for the biggest one :


Using the formula before (for
) it becomes :



16 + 8a = 52 + 36
16+8a = 88
8a = 88-16
8a = 72
a = 9
Verifying :



= 117
The biggest one :



True
By the Pythagorean theorem,

I am assuming this is a triangle.....P = a + b + c
P = 2a - 3 + 2a + 3a + 1....combine like terms
P = 7a - 2 <==