What is the reason the two lines are parallel?

The amount of money, in dollars, in an account after t years is given by a = 1000(1.03)^t. the initial deposit into the account was $_^a0 and the interest rate was _a1% per year. only enter numbers in the boxes. do not include any commas or decimal points^t. the initial deposit into the account was $__^a0 and the interest rate is % per year.

What is this inequality notation? t is less then or equal to 2

Consider the proof. given: segment ab is parallel to line de. prove: what is the missing statement in step 5?