Angles are undefined terms in plane geometry.
The true statements are:
- <em>4. </em>
<em>.</em> - <em>5. </em>
<em /> - <em>6. </em>
<em> is an obtuse angle</em> - <em>7. Its supplement must be an acute angle</em>
- <em>8. See attachment</em>
<em />
<u>Question 4</u>
The first statement is represented as:

Supplement of 
means that A and B are congruent.
The supplementary of A and B would be the same
The measure of A is then calculated as:

Subtract 22 from both sides


<u>Question 5</u>
If LP and LQ are linear pairs, then:

So:

Substitute 

Subtract 90 from both sides


<u>Question 6</u>
--- S and T are supplementary
--- T and U are complementary
Subtract both equations


Make U the subject

This means that:

Hence,
is an obtuse angle
<u>Question 7</u>
Obtuse angles are greater than 90 degrees but less than 180.
This means that their supplement must be an acute angle (i.e. less than 90)
<u>Question 8</u>
See attachment
Read more about angles at:
brainly.com/question/13954458