triangle examples grade 4

📚 Quick Study Guide

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• Definition: A triangle is a closed shape with three sides and three angles.
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• Types by Sides:
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• Equilateral: All three sides are equal.
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• Isosceles: Two sides are equal.
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• Scalene: No sides are equal.
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• Types by Angles:
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• Acute: All angles are less than 90 degrees.
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• Right: One angle is exactly 90 degrees.
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• Obtuse: One angle is greater than 90 degrees.
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• Angle Sum: The three angles of any triangle add up to 180 degrees ($180^{\circ}$).

Practice Quiz

1. Which of the following statements is true for an equilateral triangle?
   1. All sides are equal.
   2. Two sides are equal.
   3. No sides are equal.
   4. It has a 90-degree angle.
2. A triangle has angles measuring 30°, 60°, and 90°. What type of triangle is it?
   1. Acute
   2. Obtuse
   3. Right
   4. Equilateral
3. Which type of triangle has no equal sides?
   1. Isosceles
   2. Equilateral
   3. Scalene
   4. Right
4. An isosceles triangle has two sides of equal length. If those sides are 5 cm each, and the third side is 3 cm, what is the perimeter of the triangle?
   1. 8 cm
   2. 10 cm
   3. 13 cm
   4. 15 cm
5. A triangle has one angle measuring 110°. What type of triangle is it?
   1. Acute
   2. Right
   3. Obtuse
   4. Equilateral
6. What is the sum of the angles inside any triangle?
   1. 90°
   2. 180°
   3. 270°
   4. 360°
7. Which of the following is NOT a type of triangle when classified by its sides?
   1. Equilateral
   2. Isosceles
   3. Scalene
   4. Acute