Sec 5-1
Concept: Midsegments
Objective: given a midsegment, use it’s
properties to solve problems and write
coordinate proofs as measured by a s.g.
Read p. 295 and answer the
following questions
1.What is a midsegment?
2.What 2 things can you conclude
from the midsegment theorem?
Example 1:
Example 2 A:
If DE=4x+5 and GJ=3x+25,
what is DE?
Example 2 B:
If HJ==8x-2 and
DF=2x+11, what is HJ?
Example 3:
You are assembling the frame for a swing set. The
horizontal crossbars in the kit you purchased are each
36 in. long. You attach the crossbars at the midpoints
of the legs. At each end of the frame, how far apart
will the bottoms of the legs be when the frame is
assembled? Explain.
Read on p. 296 and answer the
following question
• What is a coordinate proof?
Example 4:
Place the figure in a coordinate plane in a
convenient way. Assign coordinates to each
vertex.
Isosceles Right
Triangle: Leg length
is 7 units.
Scalene Triangle: One
side length is 2m
Square: side length s
Example 5:
Find the unknown coordinates of the points
in the figure. Then show that the given
statement is true.
Helpful Formulas for Today
Use your book or a friend
• Slope:
• Midpoint:
• Distance:
Today’s Work