ACBM is a segment of a circle such that CM is the perpendicular bisector of AB.

If ICM 4 cm and IABI= 16 cm, calculate:
a the radius of the circle of which ACBM is a
segment
b the angle that chord AB subtends at the
centre of the circle
c the area of the segment.

a. 8.94 cm  b. 127°  c. 12.37 cm²

Step-by-step explanation:

a. Since CM = 4 cm is the perpendicular bisector of AB = 16 cm and r is the radius off the circle. From Pythagoras' theorem,

r² = (AB/2)² + CM²

r = √[(AB/2)² + CM²]

Substituting the values of the variables into r, we have

r = √[(16/2)² + 4²]

r = √[8² + 4²]

r = 4√[2² + 1²]

r = 4√[4 + 1]

r = 4√5 cm

r = 8.94 cm  

b. We know that the length of a chord L = 2rsin(θ/2) where r is the radius of the circle, and θ is the angle subtended by the chord AB.

Since L = 2rsin(θ/2)    and L = AB = 16 cm,

L/2r = sin(θ/2)

taking sine inverse of both sides, we have

θ/2 = sin⁻¹(L/2r)

multiplying both sides by 2, we have

θ = 2sin⁻¹(L/2r)        

substituting the values of the variables, we have

θ = 2sin⁻¹[16/(2 × 8.94)]

θ = 2sin⁻¹[16/17.88]

θ = 2sin⁻¹[0.8949]

θ = 2 × 63.49°

θ = 126.98°

θ ≅ 127°

c. The area of a segment A is given by

A = (θπ/360 - sinθ)r²/2 where θ is the angle subtended by the segment and r = radius of the circle

since θ ≅ 127° and r = 4√5 cm, substituting these values into A, we have

A = (127°π/360 - sin127°)(4√5)²/2

A = (398.93/360 - 0.7988)40

A = (1.1081 - 0.7988)40

A = 0.3093 × 40

A = 12.372 cm²

A ≅ 12.37 cm²

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.