97_knyha-1-177

B
c
A
b
a
a, b, c — äîâæèíè ñòîð³í BC, AC, AB
â³äïîâ³äíî
, , — âåëè÷èíè êóò³â A, B, C â³äïîâ³äíî
m a
, m b
, m c
— äîâæèíè ìåä³àí, ïðîâåäåíèõ
ç âåðøèí A, B, C â³äïîâ³äíî
l a
, l b
, l c
— äîâæèíè á³ñåêòðèñ, ïðîâåäåíèõ
ç âåðøèí A, B, C â³äïîâ³äíî
h a
, h b
, h c
— äîâæèíè âèñîò, ïðîâåäåíèõ
ç âåðøèí A, B, C â³äïîâ³äíî
r ³ R — ðàä³óñè âïèñàíîãî é îïèñàíîãî ê³ë
C
òðèêóòíèêà â³äïîâ³äíî
p — ï³âïåðèìåòð òðèêóòíèêà
r a
, r b
, r c
— ðàä³óñè çîâí³âïèñàíèõ ê³ë, ÿê³
äîòèêàþòüñÿ äî ñòîð³í BC, AC
³ AB â³äïîâ³äíî
AB ( x x ) ( y y )
x
0
2 1 2 2 1 2
x1 x2
, y
1
0
y1 y2
1
ax + by = c, äå a 2 + b 2 0
y = k (x – x 0
) + y 0
x x1
x x
2 1
y y1
y y
2 1
(x – a) 2 + (y – b) 2 = R 2 ,
äå M (a; b) — öåíòð êîëà, R — ðàä³óñ êîëà
S 1 ah
2 a
S 1 ab sin
2
S p ( p a) ( p b) ( p c)
S = pr
S
abc 4R
sin 0
= 0 = 30 = 45 = 60 = 90 = 180
1
2
cos 1 3
2
tg 0 3
3
2
2
2
2
3
2
1
2
1 0
0 –1
1 3 — 0
ctg — 3 1 3
3
0 —
a b c
2R
a 2 = b 2 + c 2 – 2bc cos
sin sin sin
S
r R abc a
p
4S
2 sin
r a
S
p a
sin (90 – ) = cos
cos (90 – ) = sin
tg (90 – ) = ctg
sin 2 + cos 2 = 1
sin (180 – ) = sin
cos (180 – ) = –cos
tg (180 – ) = –tg
ctg (180 – ) = –ctg
tg sin
ctg cos
cos
sin