Simplify (5m - 4)2 using the square of a binomial formula. A) 5m2 - 20m - 4
B) 25m2 – 40m + 16
C) 25m2 + 40m + 16
D) 5m2 – 40m + 4

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¯¯¯¯¯¯¯¯)?