General Triangles

• Triangles - polygons with 3 sides

  • Perimeter = a + b + c

    • a = side 1, b = side 2, c = side 3

      
      

    • ex; a = 4, b = 8, c = 2

      4 + 8 + 2

      P = 14

      
      

  • Area = 1/2b x h

    • b = base, h = height

      
      

    • ex; b = 7, h = 4

      1/2(7) x 4

      A = 14

      
      

  • Angles - always sum to 180°

    • ex; angle a = ?, angle b = 105, angle c = 40

      • 180 = ? + 105 + 40

      • angle a = 35

    
    

    • Angular bisector - A line that splits an angle into 2 pieces

  
  

  • Equilateral triangle - triangle with equal length on all sides; same angles

    • each angle = 60°

      

      
      

  • Isosceles triangle - triangle with equal length on 2 sides; 2 of the same angles

    • ex; angle a = 30, angle b = ?, angle c = ?

      • 180 = 30 + 2?

      • angle b and c = 75

  

  
  

  • Scalene triangle - triangle with all different lengths; all different angles

    

  
  

  • Right triangle - triangle with 1 right angle (90°)

    

SOLVE

• 180 = 50 + x + x

  x = 65

  𝚹 + x = 180

  𝚹 + 65 = 180

  𝚹 = 115°