Download Labeling a Right Triangle

Right Triangle Naming
Conventions
When we studied Pythagorean Theorem:
c
a
b
Or:
c
b
a
Regardless:
• Side c was always the hypotenuse of the triangle OR the
side with the longest length OR the side opposite from the
90∘ angle.
• a and b were just the names of the two other sides.
• At no point (except for 90∘) did we discuss or label other
angles of the triangle.
With Trigonometry we must reference
sides in relation to certain angles:
The angle we are referring to is termed
the reference angle and is sometimes
labeled as the Greek letter theta (Ɵ).
Ɵ
With Trigonometry we must reference
sides in relation to certain angles:
The hypotenuse never changes
and is still the longest side
of the triangle.
hypotenuse
Ɵ
With Trigonometry we must reference
sides in relation to certain angles:
The side opposite the reference
angle Ɵ is termed the opposite.
hypotenuse
opposite
Ɵ
With Trigonometry we must reference
sides in relation to certain angles:
The side next to the reference
angle Ɵ is termed the adjacent.
hypotenuse
opposite
Ɵ
adjacent
Thus:
H
O
Ɵ
A
Would the names of the sides change
if the reference angle changes?
Ɵ
H
A
O