Worked example 3 (a) Construct a line segment [XY] that has a length of 80 mm . (b) Using only a ruler, fi nd the midpoint of the line segment [XY] and mark it T . (c) Find (using a ruler): (i)
|XT| Solution
(b) (c)
(iii)
Not to scale means the diagram is not full size. It’s scaled down.
Practice questions 3.1
1. How many points are necessary to draw a straight line?
2. Label each of the following drawings as a point, line, ray, line segment or none of these. A
B C E D F
3. (i) What is the word for a straight path that goes to ∞ (infi nity) in both directions?
(ii) What is the word for a part of a line with two endpoints?
(iii) What is the word for a part of a line that has one endpoint and goes to infi nity in one direction?
(iv) What is a point?
4. What word is used to describe the orange parts in this diagram?
5. Using the diagram below: A
B C D E (i) List all the points marked.
(ii) Using letters and symbols, list ten line segments contained in the diagram.
6. Sketch a drawing of the following using a ruler and pencil only (diagrams should not exceed 6 cm).
(i) 7. [AB]
(ii) AB (i)
(iii) [EF (iv) Z
(v) [TU] Construct a line segment [AB] of 8 cm.
(ii) Using only a ruler, fi nd the midpoint of [AB] and mark it M .
8. (i) Construct a line segment [XZ] of 12 cm.
(ii) Using only a ruler, fi nd the midpoint of [XZ] and mark it T .
9. (i) Construct [XY] if |XY| = 100 mm
(ii) Using only a ruler, fi nd the midpoint of [XY] and mark it M .