How are the properties of segments and angles used to determine their measures

See below

Step-by-step explanation:

Use of following postulates and properties of line segments and angles will help in measuring them.

The Segment Addition Postulate

The Angle Addition Postulate

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.