Answer:
Number of sides are 12.
Step-by-step explanation:
Given that smallest angle of rotational symmetry for a regular polygon is 30°.
we have to find the number of sides does the regular polygon have.
If we can rotate a figure around a center point by fewer than 360° and the figure appears unchanged, then the figure has the rotation symmetry.
Now as at the centre the angle is 360 and all the angles at the centre formed equal i.e
Hence, 12 number of sides the polygon have.
Answer:
The balance in the account after 20 years will be $11280.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
In which E are the earnings, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
.
In this problem
We want to find T, when
The first step is find the earnings due to interest. So
Adding to the principal to find the balance
The balance in the account after 20 years will be $11280.