Properties of Triangles
- • Equilateral: All 3 sides equal, all 3 angles equal (60°)
- • Isosceles: 2 sides equal, 2 angles equal
- • Scalene: No sides equal, no angles equal
Part A: Identify the Triangle Type
Look at the side lengths and write whether each triangle is equilateral, isosceles, or scalene.
1. Triangle with sides: 5cm, 5cm, 5cm
Type: _____________________
2. Triangle with sides: 7cm, 4cm, 7cm
Type: _____________________
3. Triangle with sides: 6cm, 8cm, 10cm
Type: _____________________
4. Triangle with sides: 9cm, 9cm, 9cm
Type: _____________________
5. Triangle with sides: 3cm, 5cm, 7cm
Type: _____________________
6. Triangle with sides: 12cm, 8cm, 12cm
Type: _____________________
Part B: True or False
Write T for true or F for false.
1. _____ An equilateral triangle has all sides the same length.
2. _____ A scalene triangle has two equal sides.
3. _____ An isosceles triangle has at least two equal sides.
4. _____ All angles in an equilateral triangle are equal.
5. _____ A scalene triangle can have three equal angles.
Part C: Complete the Properties
Fill in the missing information about each triangle type.
Equilateral Triangle
Number of equal sides: _______
Number of equal angles: _______
Isosceles Triangle
Number of equal sides: _______
Number of equal angles: _______
Scalene Triangle
Number of equal sides: _______
Number of equal angles: _______
Part D: Challenge Question
A triangle has angles measuring 60°, 60°, and 60°. What type of triangle is it?
Answer: _____________________
Explain your reasoning:
_________________________________________________________________