Ajewelry prints a hidden watermark on the logo of all its official documents. the watermark is a chord located 0.7 cm. from the center of a circular ring that has a 2.5 cm. radius. what is the length of the chord to the nearest tenth?

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¯¯¯¯¯¯¯¯)?