What this lesson shows
Fixes a mistake
Two triangles that overlap or leave a gap do not make the rectangle. Their long sides must touch all along.
The worked example
The lesson works this one step by step: rectangle (question 1). Then your kid tries one like it on paper.
The steps
- No overlap
- No gap
- Long sides touching
- Then it makes the shape
Helping at home
Read each box aloud. After your kid draws the line, cut the paper on it and put the two parts back together, sides touching all along.
If your kid gets stuck
Sides touch all along: no gap, no overlap.
Watch it with Lux
With Lux, this lesson is a narrated video and a printed page your kid works on. Then Lux helps with the same math on their own worksheet, one question at a time.
Standards
- Common Core K.G.B.6
Compose simple shapes to form larger shapes. For example, "Can you join these two triangles with full sides touching to make a rectangle?"
Matches standards in 45 statesSee each state's code
- Alabama MA19.K.23
- Alaska K.G.6
- Arizona K.G.B.6
- California K.G.B.6
- Colorado K.G.B.6
- Connecticut K.G.B.6
- Delaware K.G.B.6
- District of Columbia K.G.B.6
- Florida MA.K.GR.1.5
- Georgia K.GSR.8.4
- Hawaii K.G.B.6
- Idaho K.G.B.6
- Illinois K.G.B.6
- Iowa K.G.B.6
- Kansas K.G.6
- Kentucky KY.K.G.6
- Louisiana K.G.B.6
- Maine K.G.B.6
- Maryland K.GR.B.9
- Massachusetts K.G.B.6
- Michigan K.G.B.6
- Mississippi K.G.6
- Missouri K.GM.C.10
- Montana MT.K.G.6
- Nebraska K.G.1.e
- Nevada K.G.B.6
- New Hampshire K.G.B.6
- New Jersey K.G.B.6
- New Mexico K.G.B.6
- New York NY-K.G.6
- North Carolina NC.K.G.6
- North Dakota K.GM.G.4
- Ohio K.G.6
- Oklahoma K.GM.1.4
- Oregon K.GM.B.6
- Pennsylvania CC.2.3.K.A.2
- Rhode Island K.G.B.6
- South Dakota K.G.B.6
- Tennessee K.G.B.6
- Utah K.G.6
- Vermont K.G.B.6
- Washington K.G.B.6
- West Virginia M.K.25
- Wisconsin M.K.G.B.6
- Wyoming K.G.6