Geometry
5.1 Midsegments of Triangles
A. Definition:
• Midsegment – the midsegment of a triangle is a segment connecting the midpoints of two sides.
• Theorem 5.1: (Triangle Midsegment Theorem): If a segment joins the midpoints of two sides of a triangle, then the segment is parallel to the third side, and half its length.
Dec 30­9:18 AM
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B. Examples. Find the value of x.
1. 12
2.
3x
18
x
3.
42
4.
2x + 4
6x + 2
4x ­ 3 Dec 30­9:19 AM
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Let's List the two different ways to solve Midsegment problems: 1. 2. Nov 14­10:25 AM
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C. Examples. Identify pairs of parallel sides.
Z
B
2.
1.
D
U
E
X
A
F
V
C
W
Y
Dec 30­9:30 AM
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D. Application: 1. The triangular face of the Rock and Roll Hall of Fame in Cleveland, Ohio is isosceles. The length of the base is 229 ft 6 in. What is the length of the highlighted segment? Explain. Dec 30­9:36 AM
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Conclusion: Find the value for the variable n. B
E
D
A
n + 6 C
3n + 4
Dec 10­8:20 AM
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5.1 HW p. 262 #s 1 ­ 20, 30 ­ 32, 35
Nov 14­10:28 AM
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