The infield of a baseball diamond is shaped like a
square. If you drew a line of symmetry in the square, you
would see 2 triangles. All triangles have 3 angles.
Triangles can be named according to the size of their
angles. An acute triangle has all 3 angles that measure
less than 90°. An obtuse triangle has one angle that
measures greater than 90°. A right triangle has one angle
that measures 90°.
All closed shapes have interior
angles. These are the angles
inside a shape. This triangle
has 3 acute angles.
Identify the interior angles on these shapes.
a.
G
c.
A
H
B
line of symmetry
C
b.
I
d.
K
D
L
E
24
J
N
M
F
25