Finding The Angles In A Triangle - Casio fx-3650P Programming Manual

16

Finding the angles in a triangle

Law of cosines：The relationship between the length
of the sides of a triangle and the angle between is
given by:
2 2 2
a = b + c –
θ
Solving this for we obtain the angle in terms of the
lengths:
2
cos b +
θ
1 –
= ---------------------------- -
2bc
ON MODE MODE
？→ Ａ：？→ Ｂ：？→ Ｃ：ＣＯＳ
Find the angle in a triangle with sides of length 3, 4 and 5.
MODE MODE
MODE MODE
Prog 1
5 EXE
EXE
4
3 EXE
To obtain the answer in radians press
executing the program.
θ
2bc cos
2 2
c – a
MODE
－１
（ （Ｂ
,-/
1
PRGM
COMP
1 MODE
２ ２ ２
） ÷２ ＢＣ） → Ｄ：Ｄ ＜ 33 STEP ＞
＋ Ｃ － Ａ
S A
S A
S A
S A
MODE MODE
a
c
1 1
P1 P1 P2 P3 P4 D R
P1 P1 P2 P3 P4 D R
P1 P1 P2 P3 P4 D R
P1 P1 P2 P3 P4 D R
MODE MODE
b
G
G
G
G
before
2
25