Answer:
- scalene
- equilateral
- isosceles
- isosceles
Explanation:
You want the triangles in the figure classified according to the relationships between the sides.
Classification by sides
Triangles are classified according to the number of sides that have the same measure.
- no sides the same — scalene
- two sides the same — isosceles
- three sides the same — equilateral
1)
The figure has no sides being marked as the same. The triangle is scalene.
2)
The figure has all three sides marked as the same. The triangle is equilateral.
3)
Two sides are marked as being the same length. The triangle is isosceles.
4)
Two sides are marked as being the same length. The triangle is isosceles.
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Additional comment
Qualifiers can be added according to the angles. However, we're not asked for that here. ∆1 looks to be an obtuse triangle. ∆2 is a right triangle.