Answer : AC = 10 inches
explanations :
• ∆ABC has perimeter = (40 ....given)
,
• Perimeter formula : ,P = sum of all three sides.
Therefore;
[tex]\begin{gathered} P\text{ = (x+3)in + (x+1)in + }2x \\ \text{ 40 = }4x\text{ in + 4 } \\ 4x\text{ = 40 - 4 } \\ \frac{4x}{4}\text{ = }\frac{36}{4} \\ \therefore x\text{ = 9 } \end{gathered}[/tex]
Since we calculated x = 9 inches ,
Therefore AC = (x+1 )inches
= (9+1)inches
= 10 inches.
