Question

in triangle abc angle c - angle a =40 and angle c - angle b=20 find angle a ,b,c

Answer 1

angle a = A, angle b = B, angle c = C
so,
C-A=40→A=C-40
C-B=20→B=C-20

also,by angle sum property
A+B+C=180
C-40+C-20+C=180
3C=180+60
C=240/3
C=80

so,
A=40
B=60
C=80

Answer 2

Let angle a=x
angle b=y
angle c=z

Angle c-angle a = 40°
z-x=40°
x=z-40°

Angle c-angle b = 20°
z-y=20°
y=z-20°

We know that,
Sum of all angles in a triangle is 180°
x+y+z=180°
(z-40°)+(z-20°)+z=180°
3z-60°=180°
3z=180+60
3z=240°
z=240/3=80°

→Angle a =x=z-40=80°-40°=40°

→Angle b=y=z-20°=80°-20°=60°

→Angle c=z=80°

Hope it helps