Awall is 8 ft high and 10 ft long. i want different colors squares, measuring 1ft by 1ft. how many different color can use.

Well every foot with be a new color so just find the area : 8•10=80. Every one foot will be a different color so there will be 80 different colors. 

Hoped I helped!

Well if you look at the color wheel its red red,orange orange orange,yellow yellow yellow,green green blue,green blue blue,violet violet red,violet red

r   = 2.65m

good luck!

cutie~