Respuesta :

1)

c^2 < a^2 + b^2 = acute

c^2 >  a^2 + b^2 = obtuse

c^2 =  a^2 + b^2 = right


so 

c^2 = 47^2 = 2209

a^2 + b^2 = 20^2 + 34^2 = 400 + 1156 = 1556

 2209 >1156

c^2 >  a^2 + b^2 = obtuse


answer is B. obtuse


2)

<A = 90, <B = <C = 45

AC = AB = 12

12^2 + 12^2 = 2 (12^2)

BC = 12√2

answer is C. 12√2 ft


3)

a square cut into 2 equal triangles (2 isosceles triangles)

So it's 45 45 90 right triangle


if hypo = 34 then side = 17√2


answer is C. 17√2 inches