11.1 Measuring Segments

Links and useful resources

• gr7's Prealgebra Course Outline START HERE<<<
• AoPS Online Textbook
• IXL Grade 7 index
• IXL Grade 8 index
• AoPS Alcumus
• IXL prealgebra practice index
• OpenSTAX Prealgebra-1 textbook

Concept summary and lesson

• Labeling segments: $\overline{AB}$ is the segment that has end-points at $A$ and $B$.
• Marking congruence on diagrams (matching tick-marks through congruent parts)
• Isosceles triangles have two congruent sides and two congruent angles
• Equilateral triangles have all three sides congruent, and all three angles congruent.
• Perimeter: the total length of the boundary of a shape.

Examples

In this diagram, $\overline{ZX}\cong \overline{WY}$ and $\overline{XM}\cong \overline{MY}$. The matching tick-marks through the segments are used to make this easy to see in the diagram.

Guided practice

• Points B and C are on segment $\overline{AD}$ such that $AC:CD=3:1$ and B is the midpoint of $\overline{AC}$. If BC = 6, what is AD?
• In the diagram below, D is the midpoint of $\overline{AC}$ and G is the midpoint of $\overline{AE}$. if $\overline{AB}=4$, what is the perimeter of ABCDEFG?
  

Homework

• #hw (math) (gr7) 11.1 Measuring Segments (p. 415) 2025-03-07