3-4 Parallel Lines and the Triangle Angle-Sum Theorem Objectives: 1) to classify triangles and find the measures of their angles 2) To use exterior angles of triangles
Example 1: Find the values of x, y, and z.
You try. Find the values of x, y, and z x= x=180 x=35 x+y= y=180 y=145 z =180 z+155=180 z=25
You can classify a triangle by its angles and sides.
Example 2: Classify the triangle by its sides and its angles. a) b) Try this
Try these. Draw and mark a triangle to fit each description. If no triangle can be drawn, write not possible and explain why. a)acute scalene b)Isosceles right c)Obtuse equiangular
Exterior angle of a polygon: angle formed by a side and an extension of an adjacent side Remote interior angles: the two nonadjacent interior angles
Example 3: Find each missing angle.
Try this one too.
Example 4: Find the value of x.
Try this. Find the value of x.