PLEASE HELP WHO EVER GET THIS RIGHT WILL MAKE U BRAINIEST

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¯¯¯¯¯¯¯¯)?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

How to simply and write the answer n a whole number