ABC that means that this shape has 3 sides what shap has 3 sides a triangle remember thtat the 3 inside angles added together equal 180 so angle a=2x+3 angle b=4x+2 angle c=2x-1 so therefor a+b+c=180 so 2x+3+4x+2+2x-1=180 group like terms 2x+4x+2x+3+2-1=180 add like terms 8x+4=180 subtracct 4 from both sides 8x=176 divide both sides by 8 x=22 subsitute a=2x+3 a=2(22)+3 a=44+3 a=47
