4. ADEF is an equilateral triangle.
E
24
20
D
F

By Pythagorean theorem

x²+GF²=EF² ( where G is the point of intersection of perpendicular lines)

now, GF=1/2 EF= 12

x²+12²=24²

x²=24²-12²

x²=432

x=√432

x=12√3

x≈20.78

answer: the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.

step-by-step explanation:

the given rate of interest i= 85%

in calculating the monthly payment for a loan with an interest rate compounded monthly, the value of the interest rate per period we use in the formula must be in decimal form.

to convert it in decimal, we divide it by 100, we get

hence, the value should be used for i in the formula of calculation the monthly payment , the interest rate per period is 0.85.