Question

O: Find angle if gt² = 5R. ​

Answer 1

Answer:

Correct option is

D

4

7

5,5r,5r

2

sides of triangle,

5+5r>5r

2

...(1)

5+5r

2

>5r ...(2)

5r+5r

2

>5 ...(3)

From (1) r

2

−r−1<0,

[r−(

2

1+

5

)][r−(

2

1−

5

)]<0

r∈(

2

1−

5

,

2

1+

5

) ...(4)

from (2),

r

2

−r+1>0⇒r∈R ...(5)

from (3),

r

2

+r−1>0

So, (r+

2

1+

5

)(r+

2

1−

5

)>0

r∈(−∞,−

2

1+

5

)∪(−

2

1−

5

,∞) ...(6)

from (4), (5), (6),

r∈(

2

−1+

5

,

2

1+

5

)