26
17
The radius of the Inscribed circle.
The inscribed circle is shown in the diagram on the
right.When the inscribed circle has radius , the area of
the appropriate triangle is:
Now, using herons formula it is possible to determine
the area of the triangle in terms of the length of the
three sides, whereby the radius of the circle is:
,
Program
?→ A:?→ B:?→ C:(A + B + C)÷2→ D:√(D(D - A)(D - B)(D-C))
÷ D → M:M < 49 STEP >
OUTPUT M : the radius of the inscribed circle
Execution Example:
For a triangle with sides of length 3, 4 and 5, the radius of the inscribed circle is 1:
S
AR
2
------
BR
2
------
CR
2
------++
ABC
++()
R
2
-----------------------------==
A
B
C
R
R
DD A
–()
DB
–()
DC
–()
D
----------------------------------------------------------=
D
ABC
++
2
---------------------=
ON
MODE MODE MODE
1
PRGM
MODE
1
COMP
1
P1
Prog
1
S A
D R
P1
P2 P3 P4
G
3
EXE
S A
D R
P1
P2 P3 P4
G
4
EXE
S A
D R
P1
P2 P3 P4
G
5
EXE
M
S A
D R
P1
P2 P3 P4
G
関数電卓事例集 .book 26 ページ 2002年9月2日 月曜日 午後6時51分