Urgent! when (1-2x)^P is expanded, the coefficient of x^2 is 40. Given that P>0 find the value of P

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¯¯¯¯¯¯¯¯)?

What is the area of mnp? 40 m2 60 m2 68 m2 127.5 m2

Don't know how to find x given these segment lengths