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(Maths)
PROPERTIES OF INCENTRE:
4.
5.
𝐂𝐄 =
𝐛𝐜
; 𝐄𝐀
𝐚+𝐜
=
𝐚𝐛
𝐚+𝐜
𝐀𝐅 =
𝐛𝐜
; 𝐁𝐅
𝐚+𝐛
=
𝐚𝐜
𝐚+𝐛
∠𝐁
∠ BIC = 1800 -- 𝟐
=1800 --
− ∠𝐂
𝟐
∠(𝐁+𝐂)
𝟐
= 1800 −
Same as
𝐚𝐜
𝐚𝐛
; CD =
𝐛+𝐜
𝐛+𝐜
BD =
(𝟏𝟖𝟎−𝐀)
𝟐
= 90 + ∠𝐀
𝟐
∠𝐁
∠ AIC = 90 + 𝟐
∠𝐂
∠ AIB = 90 + 𝟐
6. Radius of in circle = r =
∆
where, s= semi-perimeter of ∆
𝒔
and ∆= 𝐚𝐫𝐞𝐚 𝐨𝐟 𝐭𝐫𝐢𝐚𝐧𝐠𝐥𝐞
Date of Release – 19-MAR-16
SUBJECT- MATHS
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