AMC 8 formulas

Question 1

1²+2²+3²…n²

Answer 1

((n)(n+1)(2n+1))/6

Question 2

Stewart’s Theorem

Answer 2

c²n+b²m=m²n+n²m+d²m+d²n

Question 3

Pick’s Law

Answer 3

A = B/2+I-1

A = area of the bounded region
B = number of boundary points
I = number of interior points

Question 4

Radius of circle inscribed in triangle

Answer 4

r=^A/_s

Where A= triangle’s area

s = triangle’s semiperimeter