help me with this question

Answer:
∆QRS is an obtuse triangle
Step-by-step explanation:
[tex]x + 2x + 8x - 40 = 180 \\ 11x = 220 \\ x = 20[/tex]
[tex] < q = 20 \\ < r = 8(20) - 40 = 120 \\ < s = 2(20) = 40[/tex]
<R = 120° > 90° which makes this an obtuse triangle