Plz help it really hard

12. the amount of money in a bank account decreased by 21.5% over the last year. if the amount of money at the beginning of the year is represented by ‘n', write 3 equivalent expressions to represent the amount of money in the bank account after the decrease?

Given: m∠ adb = m∠cdb ad ≅ dc prove: m∠ bac = m∠bca lol

Acircle has a circumference of 7.850 units. what is its radius?