Question

fine the measure of the third angle . 30 degree ,80 degree .

Answer 1

if the measurements of triangle are 30 and 80 then third angle is 70
because of property of triangle.80+30+x=180
x=180-110=70

Answer 2

$180 - (30 + 80)= 70$
This is due to the property of triangle , having 180°