please answer the following ...i will mark as brainliest..need explanation
Answers
Answer:
(1) 9√3 ( 1 + √3 ) / π²
Step-by-step explanation:
Let R be the radius.
The circumference of the circle is 3 + 4 + 5 = 12, so
2πR = 12 => R = 6/π.
The radii to the vertices divide the triangle into three isosceles triangles. Each of these triangles has area
(1/2) × R² × sin( the angle at the centre of the circle )
= ( 18 / π² ) × sin ( the angle at the centre of the circle )
The angle subtended at the centre by the length 3 arc is (3/12)×360° = 90°.
The angle subtended at the centre by the length 4 arc is (4/12)×360° = 120°.
The angle subtended at the centre by the length 5 arc is (5/12)×360° = 150°.
Adding together the areas of the three smaller triangles, the area of the full triangle is then...
( 18 / π² ) × ( sin 90° + sin 120° + sin 150° )
= ( 18 / π² ) × ( 1 + sin 60° + sin 30° )
= ( 18 / π² ) × ( 1 + √3/2 + 1/2 )
= ( 18 / π² ) × ( ( 3 + √3 ) / 2 )
= ( 9 / π² ) × ( 3 + √3 )
= 9 ( 3 + √3 ) / π²
= 9√3 ( 1 + √3 ) / π²
by using concept of properties of triangles
answer is 1 option