The figure shows a triangle with exterior angle w.

Question

The triangle has interior angles x, y, and z, and exterior angle w. Angles x and w are supplementary angles.

Question
The measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles.



Move options to the blanks to complete the proof.

Response area with 8 blank spaces
Statement Reason
the measure of angle x plus the measure of angle w equals 180 degrees

Straight angles add to 180 degrees.

Blank space 16 empty
equals 180 degrees minus
Blank space 17 empty

Subtraction

​the measure of angle x plus the measure of angle y plus the measure of angle z equals 180 degrees

The sum of the angle measures of a triangle equals 180 degrees.

Blank space 18 empty
plus
Blank space 19 empty
​equals 180 degrees minus
Blank space 20 empty

Subtraction

Blank space 21 empty
plus
Blank space 22 empty
​equals
Blank space 23 empty

Substitution

Answer 1

Blank space 16: x
Blank space 17: 180
Blank space 18: x
Blank space 19: y
Blank space 20: 180
Blank space 21: x+y
Blank space 22: z
Blank space 23: 180