If the vertices of a triangle A,B,C are A(0,0),B(2,1),C(9,−2) then cosB=
In a triangle ABC, a : b : c = 4 : 5 : 6. The ratio of the radius of the circumcircle to that of the incircle is
Compute each of the following:
(a). 15+(-5)+15+(-7)
(b). 34+(-20)+16+(-10)
(c). 32+16+9+(-70)
(d). -3+(-2)+(-5)+7
(e). -53+(-17)