44. An angle is a right angle
only if:
You’re expressly told, “this
is a right angle”.
You see the
perpendicular symbol ().
You see the box in the
angle.
L1
L2
69. a
b
c
A
B
C
The sum of the length of two sides must be greater than the length of the third side.
+
70. In any triangle, the sum of the interior
angles is 180o.
a b
c A B
C
A B C 180
71. The largest side is the hypotenuse and the
sides adjacent to the right angle (C = 90o) are
the legs.
C A
B
a
c
b
180
90
A B C
A B
72. The measure of exterior angles of a triangle
is equal to the sum of the two remote
interior angles.
a
b
c
y
x
z
360
x b c
y a c
z a b
x y z
73. The square of the length of the hypotenuse
is equal to the sum of the squares of the
lengths of the legs of the triangle.
a
b
c
2 2 2 a b c
It works only in right triangles.
78.
1
2
A base height
The term "base" denotes any side, and
"height" denotes the length of a
perpendicular from the vertex opposite
the side onto the line containing the
side itself.