`a+(b+c)=(a+b)+c` is called __ property.

a(b+c)=ab+ac is called ___ property.

a+b=b+a is called ___ property.

(ab)c=a(bc) is called…… property.

a+b=b+a is called……..property.

Additional Bits : In b:c , c is called _____________ .

a, b, c are three vectors such that |a| = 1, |b| = 2, |c| = 3 and b, c are perpendicular. If projection of b on a is the same as the projection of c on a, then |a-b + c| =

If a,b,c are vector of length 4,4,5 respectively and a,b,c are perpendicular to b+ c , c + a, a+ b respectively, then |a + b + c| =