guys please help...........................................................................

[tex]\bold{\huge{\underline{ Solution }}}[/tex]
Here, we have
By using Angle sum property
That,
[tex]\bold{\angle{X + }}{\bold{\angle{Y + }}}{\bold{\angle{Z = 180}}}{\degree}[/tex]
Subsitute the required values,
[tex]\sf{ 60{\degree} + 20{\degree} + C = 180{\degree}}[/tex]
[tex]\sf{ 80{\degree} + C = 180{\degree}}[/tex]
[tex]\sf{ C = 180{\degree} - 80{\degree}}[/tex]
[tex]\sf{ C = 100}{\degree}[/tex]
Thus, The value of C is 180°
We have to find the measurement of Angles A and B
Here,
[tex]\sf{\angle{B + }}{\sf{\angle{ x + }}}{\sf{\angle{C = 180}}}{\degree}[/tex]
[tex]\sf{\angle{ B + 20{\degree}+ 100{\degree} = 180{\degree}}}[/tex]
[tex]\sf{\angle{ B + 20{\degree} = 180{\degree}- 100{\degree}}}[/tex]
[tex]\sf{\angle{ B = 80{\degree} - 20{\degree}}}[/tex]
[tex]\sf{\angle{ B = 60{\degree}}}[/tex]
[tex]\sf{\sf{A + }}{\sf{\angle{B + }}}{\sf{ 100{\degree} = 180}}{\degree}[/tex]
[tex]\sf{\angle{ A + 60{\degree} = 180{\degree} - 100{\degree}}}[/tex]
[tex]\sf{\angle{ A = 80{\degree} - 60{\degree}}}[/tex]
[tex]\sf{\angle{ A = 20{\degree}}}[/tex]
Hence, The measure of Angles A, B and C are 20° , 60° and 100° .