Respuesta :

Step-by-step explanation:

 Before we proceed, we must understand that we are dealing with a system of right angled triangles.

  There are two types of right angle triangles';

          45° - 45° - 90°                30° - 60° - 90°

In 45° - 45° - 90°, the adjacent is equal to the opposite

    30° - 60° - 90°, there are three different sides

The longest side faces 90°, the shortest side will face the smallest angle and the intermediate will face 60°

A.

 To find AB, use Pythagoras theorem;

          AB²  = AC² + BC²

          AB²  = 13² + 4²

           AB²  = 169 + 16  = 185

           AB = √185  = 13.6

AB = 13.6

Angle A = 30°

Angle B = 60°

B.

   AB² = BC² + AC²

 The unknown is AC;

      AC² = AB² - BC²

      AC²  = 5²  - 4²

       AC² = 9

       AC = √9 = 3

Angle A = 60°

Angle B = 30°

C.

        AB²  = AC² + BC²

 Insert the parameters and find AC;

        AC² = AB² - BC²

        AC²  = 11²  - 4.4²

        AC²  = 101.64

         AC  = √101.64

         AC = 10.1

Angle A = 30°

Angle B = 60°  

AC = 13