Download What makes it SIMILAR?

Guided Discovery in Geometry
What makes it SIMILAR?
(understanding Similar Polygons)
Guided Investigation #1: The Set-up
Let’s explore these the topic of “SIMILARITY” by looking at these two polygons. Hexagon MNOPQR is an
enlargement of hexagon ABCDEF.
B
C
O
N
D
A
F
E
P
M
R
Q
Step 1: Use a protractor to measure all of the ANGLES in each hexagon. Record them in the table below:
∠A
∠B
∠C
∠D
∠E
∠F
∠M
∠N
∠O
∠P
∠Q
∠R
MEASUREMENT
MEASUREMENT
Compare the measurements of the angles. What do you notice?
Step 2: measure THE SEGMENTS of each polygon to the nearest centimeter & record them in the table below:
AB
BC
CD
DE
EF
FA
MN
NO
OP
PQ
QR
RM
MEASUREMENT
MEASUREMENT
Compare the length of the segments (sides) of each hexagon. How do these differ from the angles?
Write the ratios comparing the length of the segments in hexagon ABCDEF to those of hexagon
MNOPQR.
Step 3: Compare the ratios of sides within each polygon: AB with MN and EF with QR .
BC
What do you notice?
NO
CD
OP
Terms: From this investigation, you should be able to understand the basic ideas of what makes two polygons
SIMILAR. Can you come up with a good definition of SIMILARITY?
Similar Polygons.doc Created by S. Middleton
1
revised: 11/17/2009