Subscribe

5th grade · Math · Unit 9 of 15

Triangles & Moves

Triangles, views and transformations

What your child practices

Sorting triangles by sides and angles, knowing when a triangle can be made, seeing 3D objects from different views, and sliding, flipping and turning shapes on a grid.

Alabama Course of Study content standard: 5.21 · classifying triangles by their side lengths and angles

How we explain it

Children can open this short lesson before they practice.

  1. Triangles are named by sides (equilateral, isosceles, scalene) and by angles.
  2. Congruent shapes match exactly in size and shape.
  3. Coordinates (x, y): go across x, then up y.

Example: A triangle has sides 5 cm, 5 cm and 8 cm. What type is it by its sides? Two sides are equal. That makes it isosceles. Answer: Isosceles

Triangles & Moves in Alabama

In the Alabama Course of Study, this is unit 9 of 15 in 5th grade Math, after Parallel Lines and Quadrilaterals and before Converting Units.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Alabama State Department of Education (ALSDE)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A triangle has angles 20°, 40°, 120°. What kind of triangle is it?

    • right triangle
    • obtuse triangle
    • acute triangle

  2. Question 2

    A parallelogram is turned, flipped or slid. Is it still congruent to the original?

    • No, it gets bigger
    • No, it becomes a different shape
    • Yes, moving a shape does not change its size or shape

  3. Question 3

    Point A is at (7, 8). It moves 2 right and 3 down. Where does it land?

    001122334455667788991010111112121313141415151616A
    • (9, 5)
    • (9, 11)
    • (5, 9)

  4. Question 4

    What is the top view of a cube?

    • a triangle
    • a square
    • a circle

  5. Question 5

    A triangle has sides 8 cm, 8 cm, 8 cm. What kind of triangle is it?

    • equilateral
    • isosceles
    • scalene

  6. Question 6

    A triangle has sides 4 cm, 5 cm, 6 cm. What kind of triangle is it?

    • isosceles
    • scalene
    • equilateral

More 5th grade