Under the U.S. Rule, unpaid accrued interest is accumulated separately and is not added to principal. In addition, interest is not calculated until a payment is made.
Principal = $12 000.00
1st period = 40 days
Interest on 1st period
= $12 000 × 0.11 × 40/360 Interest = 146.67
Principal + interest = 12 146.67
-Partial payment = 4 000.00
Adjusted balance = $ 8 146.67
Roger's adjusted balance after the first payment is $8146.67.
to find the area you need to do pi times the radius square and to find the radius squared you just times it by its self so 13 times 13 which is 169 and pi is 3.14