Question

solve this question .​

Answer 1

Answer:

[a, b , c are correct option ]

Step-by-step explanation:

(a)option checking

TanB/2 = OD/BD = 4/6= 2/3-----(1)

TanC/2 = 0D /CD= 4/8 = 1/2-------(2)

(a) We know A + B + C = π

<A+<B+<C/2 = π/2

<B /2 + <C/2 = π/2- <A/2

tan(<B/2+<C/2)= tan(<π/2-<A/2)

=>TanB/2+tanC/2/1-tanC/2 = cotA/2

=>2/3 + 1/2 /1-2/3*1/2 = cotA/2

=> 7/6/2/3 = cotA/2

=> 7/4 = cotA/2

and 4/7 = tanA/2 -----------(3)

tanB/2*tanC/2 = s-a/s

2/3*1/2 = s-14/s

1/3 = s-14/s

2s = 42

s= a+b+c/2 = 21 cm

a+b+c = 42 perimeter of ∆

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Checking option (B)

Area of triangle = rs = 4* 21 = 84cm²

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Checking option (c)

TanA/2, tanB/2 , tanC/2 all less than 1

hence triangle is acute angle .

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option D is clear from option (c) its incorrect statement .

• Hope it's helpful

Answer 2

Answer is given in the pic.