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Section 5.4: Midsegment Theorem. Goals. Identify the midsegments of a triangle Use properties of midsegments of a triangle. Anchors. Analyze characteristics and properties of two and three dimensional geometric shapes and demonstrate understanding of geometric relationships
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Section 5.4: Midsegment Theorem Goals • Identify the midsegments of a triangle • Use properties of midsegments of a triangle Anchors • Analyze characteristics and properties of two and three dimensional geometric shapes and demonstrate understanding of geometric relationships • Identify and/or use properties of triangles
Using Midsegments of a • Midsegment of a A E D C B F
E D F Theorem 5.9: Midsegment Theorem • The midsegment of a is DE || BC and DE = EF || AB and EF = DF || AC and DF =
D E F AB = 8 , AC = 12 , BC = 14 Find the perimeter of ABC. Find the perimeter of DEF. The perimeter of a triangle formed by the midsegments is
75 108 DAE = 75, BDE = 108 Find the missing angles in the figure. Explain how you found the missing angles.
The midpoints of the sides of a are J (-3 , 4) , K (1 , 10) , and L (0 , 5). What are the coordinates of the vertices of the ? Graph it.
The midpoints of the sides of a are A (8 , 4) , B (4 , 6) , and C (10 , 8). What are the coordinates of the vertices of the ? Label them D, E, & F. Graph it. Use the slope of each midsegment to find the parallel line through the other midpoint. Connect all of the parallel lines. What is the perimeter of DEF. (Round to one decimal place) The perimeter of DEF ≈