Geometry: An Interactive Journey to Mastery

2. Are the two triangles in Figure 10.12 similar?
   If so, what is the scale factor?


3. D௘ͽ 6KRZWKDWWKHUHLVQR$$$$SULQFLSOH
   for quadrilaterals.
    7KDWLV¿QGH[DPSOHVRIWZRTXDGULODWHUDOVWKDWKDYHWKHVDPHDQJOHVEXWDUHFOHDUO\QRWVLPLODU
   E௘ͽ 6KRZWKDWWKHUHLVDOVRQR6666SULQFLSOHIRUTXDGULODWHUDOV


4. Explain why ‘#‘SNA A in Figure 10.13.


5. Explain why each interior angle of an equilateral triangle must have measure 60°.


6. An angle bisector is drawn from the apex of an isosceles triangle.
   Suppose that it intersects the base at point Mͼ௘6HHFigure 10.14௘ͽ
   Prove:
   D௘ͽ M is the midpoint of AC.
   E௘ͽ BMAAC.

1.6

3.0

7.2

6.0 28.8

12.0

Figure 10.12

25 24 30

N

S P A

Figure 10.13

B

AM C

xx

Figure 10.14