Question

The sum of two angle of triangle is 80° and their defference is 20°, then the smallest angle?

Answer 1

smallest angle is 30

Answer 2

let angle A+B=80....1
and
angle A-B=20......2

adding equation 1 and 2,we get
A+B+A-B=80+20
2A=100
angle A=50
now,
A+B=80
50+B=80
B=30

now,
A+B+C=180(∆ sum property)
50+30+C=180
80+C=180
C=100.


the smallest angle will be angle B=30°