#1) (b)
#2) (d)
#3) (d)
My explanations are the same as your previous questions.
Answer:
Part a) The measure of the missing angle is 
Part b) The triangle of the figure is a right triangle
Part c) The triangle of the figure is a scalene triangle
Step-by-step explanation:
we know that
The sum of the interior angles of a triangle is equal to 
so
Let
x------> the missing angle
we know that

solve for x

The triangle of the figure is a right triangle --------> by its angles
Because the triangle has an angle measure of 
The triangle of the figure is a scalene triangle --------> by its sides
Because the three angles and the three sides measures are different
What is the problem?? I would love to help