Need help on this question been stuck on it

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

Indicate the formula for the following conditions: p^c(n,r)=

|2x - 6| > 10 {x|x < -8 or x > 2} {x|x < -2 or x > 8} {x|-2 < x < 8}