Scalene, isosceles, and equilateral triangles

Learning Objectives Identify the three side lengths of any given triangle. Define scalene, isosceles, and equilateral triangles based on their side properties. Classify a triangle as scalene, isosceles, or equilateral when given its side measurements. Draw examples of scalene, isosceles, and equilateral triangles using a ruler. Distinguish between the characteristics of scalene, isosceles, and equilateral triangles. Explain why an equilateral triangle is also a special type of isosceles triangle. Have you ever noticed how many different shapes we see every day? 📐 From pizza slices to roof tops, triangles are everywhere! But did you know not all triangles are the same? In this lesson, we'll explore three special types of triangles: scalene, isosceles, and equilateral....

TermDefinitionExample TriangleA polygon (a closed shape with straight sides) that has exactly three sides and three angles.A slice of pizza is often a triangle. Side LengthThe measurement of how long each side of a triangle is.A triangle might have sides that are 3 cm, 4 cm, and 5 cm long. Scalene TriangleA triangle where ALL three sides have DIFFERENT lengths.A triangle with sides measuring 3 inches, 5 inches, and 7 inches. Isosceles TriangleA triangle where AT LEAST TWO sides have EQUAL lengths.A triangle with sides measuring 4 cm, 4 cm, and 6 cm. Equilateral TriangleA triangle where ALL THREE sides have EQUAL lengths.A triangle with sides measuring 5 meters, 5 meters, and 5 meters. VertexA corner point of a triangle where two sides meet. A triangle has three vertices.In a triangle ABC,...

Scalene Triangle Rule $a \neq b \neq c$ If a triangle has three sides of different lengths, it is a scalene triangle. No two sides are the same. Isosceles Triangle Rule $a = b$ (or $b = c$, or $a = c$) If a triangle has at least two sides of the same length, it is an isosceles triangle. Equilateral Triangle Rule $a = b = c$ If a triangle has all three sides of the same length, it is an equilateral triangle.