The clock below is in the shape of a regular pentagon. what is x , the degree measure that the bottom side of the clock makes with the surface of the table

If the clock below is in the shape of a regular pentagon, then the x and the degree measure that the bottom side of the clock makes with the surface of the table is 72 degree.  The correct answer to the following given statement above is 72 degree.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

b.-4 units

all you   do is count how many times you move