Points & Lines
Look at the two endpoints A and B. What is the name for the part of a line that has endpoints A and B?
line segment AB
Which angle is a right angle: an angle that measures 90∘, 45∘, or 120∘?
Right angle = 90∘
How many sides does a pentagon have?
Pentagon has 5 sides
What does it mean for a figure to have a line of symmetry? Write one sentence.
A line of symmetry divides a figure into two matching halves.
How many right angles are in a standard rectangle?
Rectangle has 4 right angles.
On the picture, line AB and line CD never meet. What word describes the relationship between AB and CD?
parallel
If an angle is greater than 90∘ but less than 180∘, what is it called? Give one example of a possible measure (in degrees).
Obtuse; example: 108∘.
Which group (A, B, or C) includes a hexagon? Explain your choice in one short sentence.
Group C — contains a 6-sided polygon.
For each shape shown, indicate whether it is symmetrical.
If the shape is symmetrical, where would we draw the line of symmetry?
(parallelogram, scalene triangle)
Teacher check
Through the parallelogram
Draw two angles that would add up to 180∘
What do we call each of those angles?
Ex: 130∘+50∘=180∘
Obtuse and acute, or right and right
Ray PQ starts at P and goes through Q. How would you write the name of this ray?
→
PQ
or
ray PQ
Sketch an angle that measures 67∘ using a protractor. Label the vertex and the two rays.
Sketch check for 67∘ = teacher check.
Which of these triangles would be equilateral:
one with sides 3 in, 3 in, 5 in;
one with sides 2 in, 2 in, 2 in;
or one with angles 70∘, 90∘, 20∘?
Choose the correct option and explain why.
Option with sides 2,2,2 is equilateral.
A figure is folded along a line and the two halves match exactly. Name the line of symmetry and draw it on a provided shape.
(Teacher: provide an asymmetrical shape and a symmetrical shape.)
Teacher check
Find something in your room or in nature that has a line of symmetry. Show and explain.
Teacher check
Draw a short sketch showing a line, a line segment, and a ray. Label each one clearly.
Teacher checks
On a diagram, an angle is split into two angles: one is 25∘ and the other is 40∘. What is the whole angle’s measure? Write your calculation.
___∘=25∘+40∘
Answer= 65∘
Draw an example of a polygon that has two pairs of parallel sides and no right angles. Label the parallel sides and mark the angles.
What would this polygon be called?
Parallellogram, rhombus, quadrilateral
Draw a figure and then draw its line of symmetry. Then cross out a similar figure that is not symmetric.
Teacher: provide three shapes—students mark which to cross out and draw symmetry line on the symmetric one.
∠ABC is an acute angle. What could the size of ∠ABC be?
Anything less than 90∘
Two lines are shown that form a small square corner (right angle) where they meet. Are the lines perpendicular, parallel, or neither? Explain in one sentence.
Perpendicular because they meet to form a right angle.
Point N is inside square JKLM. Given ∠JKM=45∘ and ∠MKN=22∘, find ∠NKL.
∠NKL = 23∘
Ben draws a triangle where no sides and no angles are equal. What is the name of that triangle? Draw and label the three unequal angles with degree measures.
"Scalene triangle" (no equal sides or angles).
Teacher check
Describe a transformation that moves a figure up 3 units on a coordinate grid. Then sketch the original and the transformed figure on a small grid.
"Translate up 3 units" and sketch check.
A polygon has 7 sides. How many sides does it have? What is its name? Draw a simple version and label it.
Heptagon has 7 sides (draw and label).