Answer:
90+5x+x+10=180(interior angle of triangle)
100+6×=180
6x=180-100
6x=80
[tex]x = \frac{80 }{6} \\ x = \frac{40}{3} \\ now \\ 5x = 5 \times \frac{40}{3} \\ = \frac{200 }{3} \\ = 66 \frac{2}{3} \\ a = 5x = \ 66 \frac{2}{3} [/tex]
