Why is it important to represent these unknown values with variables

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.

Benjamin believes that ¼ % is equivalent to 25%. is he correct? why or why not?

Marking brainliest for original answer.. are these two triangles similar? how can you tell?