Mon Prof Augmenté
Three Corners on a Straight Edge
Age 11 · Maths
The three inside corners of a triangle can be placed along a straight edge. The red, blue, and yellow corners fit together to make one straight line.
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Age 11: open this week
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In the picture
- A red triangle corner: one of the three inside angles.
- A blue triangle corner: another inside angle of the same triangle.
- A yellow triangle corner: the third inside angle, completing the straight line.
Examples
- A triangular road sign: if two corner angles are known, the third can be found.
- A triangular roof support: its three inside angles add to a straight angle.
Key takeaways
- The three inside angles of any triangle add to 180 degrees.
- If you know two angles, subtract their sum from 180 to find the missing angle.
Quiz: Three Corners on a Straight Edge (Age 11)
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The three inside angles of any triangle always add up to how many degrees?
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A triangle has two angles that add up to 130 degrees. What is the third angle?
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When the three inside angles of a triangle are placed together, what do they make?
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