Can someone please help me with math.

Acircle has a radius of 5/6 units and is centered at (3.6, 7.8) write the equation of this circle

Asquare has a perimeter of sixteen centimeters. what is the length of each of its sides? a. 8 cm c. 9 cm b. 4 cm d. 10 cm select the best answer from the choices

2. explain in words how you plot the point (4, −2) in a rectangular coordinate system.