Each answer shows a complete solution and a scoring guide. Award points for the correct equation and reasoning, not only for the final number. Accept equivalent definitions and notation that names the endpoint first.
Question 1: Undefined terms and definitions (2 points)
- Point, line and plane.
- A ray is a part of a line that consists of one endpoint and all the points of the line extending in one direction from it.
Scoring: 1 point for all three terms; 1 point for a definition that includes one endpoint and extension in one direction only.
Question 2: Naming rays and points (2 points)
- Ray BC (endpoint first).
- Ray BA and ray BC share endpoint B and form line AC: ray BA and ray BC.
Scoring: 1 point for each part. Award the first point only if the endpoint is named first.
Question 3: Segment addition (3 points)
- \((2x+3)+(3x-1)=37\), so \(5x+2=37\) and \(5x=35\). x = 7.
- \(KL=3(7)-1=20\). KL = 20.
Scoring: 1 point for the correct equation, 1 point for x = 7, 1 point for KL = 20.
Question 4: Midpoint (2 points)
- \(5x-4=3x+8\), so \(2x=12\) and x = 6.
- \(RN=5(6)-4=26\) and \(NS=3(6)+8=26\), so \(RS=26+26=52\). RS = 52.
Scoring: 1 point for each part.
Question 5: Angle addition (3 points)
- \((3x+7)+(5x-1)=118\), so \(8x+6=118\) and \(8x=112\). x = 14.
- \(m\angle BOC\)\(=5(14)-1=69^{\circ}\). 69°.
Scoring: 1 point for applying the Angle Addition Postulate, 1 point for x = 14, 1 point for 69°.
Question 6: Complement problem (2 points)
Let the complement be \(y^{\circ}\). The angle is \(4y^{\circ}\) and they add to \(90^{\circ}\): \(y+4y=90\), so \(5y=90\) and \(y=18\).
Complement 18°; angle 72°. Check: \(4\times 18=72\) and \(72+18=90\).
Scoring: 1 point for a correct equation, 1 point for both measures.
Question 7: Vertical angles and linear pairs (3 points)
- Vertical angles are congruent: \(6x-8=4x+14\), so \(2x=22\) and x = 11.
- \(m\angle 1\)\(=6(11)-8=58^{\circ}\). 58°.
- Angles 1 and 2 are a linear pair, so they are supplementary: \(m\angle 2\)\(=180-58=122^{\circ}\). 122°.
Scoring: 1 point for each part; part (c) needs the measure and the linear pair reason.
Question 8: Angle bisector (3 points)
- A bisector makes equal angles: \(4x-6=2x+14\), so \(2x=20\) and x = 10.
- Each part is \(4(10)-6=34^{\circ}\), so \(m\angle ABC\)\(=34+34=68^{\circ}\). 68°.
- \(68^{\circ}< 90^{\circ}\) (less than a right angle), so the angle is acute.
Scoring: 1 point for each part.
20 points
See every chapter on the Geometry math page.


