Question

*two angles of a triangle are of measure 30 degree and 70 degree respectively find the third angle*​

Answer 1

Ist angle =  30°

IInd angle  =  70°

IIIrd angle  =  x

70° + 30° + x =  180°       { Angle sum property of a Δ }

100° + x  =  180°

x  =  180° - 100°

x  =  80°

Answer 2

Given

The angles of triangle are 30° and 70°

Let the third angle be x

angle 1 + angle 2 + angle 3 = 180° (Angle Sum Property)

30° + 70° + x = 180°

100° + x = 180°

x = 180° - 100°

x = 80°

The third angle = 80°