Answer:
So the triangle ABC is an isosceles triangle
Explanation:
By definition the perimeter of a triangle is equal to the sum of the lengths of its sides.
In this case we know that the perimeter is 63
The lengths of its sides depend on x.
![AB = 6x\\AC = 4x + 6\\BC = 8x + 3](https://img.qammunity.org/2020/formulas/mathematics/high-school/5pduxef5sdqi71015gv3puaznbyacc7ln9.png)
So:
![6x + 4x + 6 + 8x + 3 = 63](https://img.qammunity.org/2020/formulas/mathematics/high-school/45wh4j02h784arr1ux1uedp7tl4e46bsp5.png)
Now we solve for the variable x.
![6x + 4x + 6 + 8x + 3 = 63](https://img.qammunity.org/2020/formulas/mathematics/high-school/45wh4j02h784arr1ux1uedp7tl4e46bsp5.png)
![18x + 9 = 63](https://img.qammunity.org/2020/formulas/mathematics/high-school/n31jxhtojnvg4ykt0z23idtgpci4dtrxma.png)
![18x = 54](https://img.qammunity.org/2020/formulas/mathematics/high-school/kmny955hnnlzj4hae7hd7zq5mgahp9mnln.png)
![x=(54)/(18)\\\\x=3](https://img.qammunity.org/2020/formulas/mathematics/high-school/rtm40z4q2cagbfonoh5yp224rvhlucd4x1.png)
Therefore:
![AB = 6(3)=18\\AC = 4(3)+6=18\\BC = 8(3) + 3=27](https://img.qammunity.org/2020/formulas/mathematics/high-school/x9neqedqizr1lwcgvdrlid39p5i1hocn7a.png)
The triangle has two sides of equal length. The triangles that have two equal sides are the isosceles triangles.
So the triangle ABC is an isosceles triangle