Answer:
48
Step-by-step explanation:
All interior angles of a triangle add up to 180.
[tex](x+21)+(x+23)+(x+61)=180[/tex]
If you wanted to you could subtract 21, 23, and 61 from 180.
[tex](x+21)+(x+23)+(x+61)=180\\x+21+x+23+x+61=180\\3x+105=180\\3x=75[/tex]
Then take then number that's left and divide it by three, since they are all in addition to the same variable.
[tex]\frac{3x}{3}=\frac{75}{3}\\ x=25[/tex]
Then add 25 to 23 which is 48.
