Triangle Song - YouTube Triangle Song - YouTube
Triangles A triangle is a 3- sided polygon. Every triangle has three sides and three angles. When added together, the three angles equal 180°.
Acute Triangles An acute has three angles that are less than 90°. Remember AAAA. ALL ANGLES ARE ACUTE!
Obtuse Triangles An obtuse triangle is a triangle in which one of the angles is greater than 90° and the other two angles are acute. One obtuse angle and Two acute angles
Right Triangles A right triangle is triangle with an angle of 90°. One right angle and two acute angles
Scalene Triangles A triangle with three unequal sides. The “mean scalene” doesn’t want to get along. All of the sides are different lengths!
Isosceles Triangles To remember this triangle….. “eye” …soceles” It will remind me that I have 2 eyes. The “e-l-e-s” at the end is close to how we spell the word eyes. An isosceles triangle has 2 sides that are the same (equal in length). It has at least 2 acute angles. An isosceles triangle is a triangle with two equal sides. When two sides are the same we call them CONGRUENT.
Equilateral Triangles An equilateral triangle is a triangle with all three sides of equal length All the angles will be the same size (acute). Equilateral you are so fine, all your sides are the same size!
Triangle Quiz Please complete the following quiz that covers the information that was just presented to you.
Question 1 If a triangle has three unequal sides it is a ______ triangle. A) Scalene B) Obtuse C) Isosceles Answer: A) Scalene
Question 2 A triangle which has three equal sides is a ______ triangle. A) Acute B) Equilateral C)Scalene Answer: C) Equilateral
Question 3 A triangle with (at least) two equal sides is a ______ triangle. A) Scalene B) Isosceles C) Congruent Answer: B) Isosceles
Question 4 Two triangles that are equal are called ______ triangles A) Acute B) Obtuse C) Congruent Answer: C) Congruent
Question 5 A triangle with all three sides of equal length is a ______ triangle. A) Equilateral B) Right C) Equiangular Answer: A) Equilateral
Question 6 A triangle with an angle of 90° is a ______ triangle. A) Acute B) Right C) Congruent Answer: B) Right
Question 7 A triangle in which all three angles are less than 90° is a ______ triangle. A) Right B) Acute C) Scalene Answer: B) Acute
Question 8 A triangle in which one of the angles is greater than 90° is a ______ triangle. A) Obtuse B) Isosceles C) Acute Answer: A) Obtuse
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