Step 1: Find the radius of the circle.
The perimeter (circumference) of the circle is given as 88 cm.
The formula for the circumference of a circle is C=2πr.
We are given C=88 cm and π=722.
88=2×722×r
88=744r
To find r, multiply both sides by 447:
r=88×447
r=2×7
r=14cm
Step 2: Calculate the length of the chord AB.
The chord AB subtends an angle of 70∘ at the centre of the circle. Let the centre be O.
In △OAB, OA=OB=r=14 cm.
We can use the formula for the length of a chord: AB=2rsin(2θ).
Here, r=14 cm and θ=70∘.
AB=2×14×sin(270∘)
AB=28sin(35∘)
Using a calculator for sin(35∘):
sin(35∘)≈0.573576436
AB=28×0.573576436
AB≈16.06013999
Rounding to three decimal places:
AB≈16.060cm
The length of the chord AB is 16.060cm.
Step 3: Calculate the area of the minor sector OAB.
The formula for the area of a sector is Asector=360∘θ×πr2.
Here, θ=70∘, r=14 cm, and π=722.
Asector=36070×722×(14)2
Asector=367×722×196
Asector=3622×196
Asector=922×49
Asector=91078
Asector≈119.777777...cm2
Step 4: Calculate the area of the triangle OAB.
The formula for the area of a triangle with two sides and the included angle is A△=21absin(C).
In △OAB, OA=OB=r=14 cm, and the included angle ∠AOB=70∘.
A△OAB=21r2sin(θ)
A△OAB=21(14)2sin(70∘)
A△OAB=21×196×sin(70∘)
A△OAB=98sin(70∘)
Using a calculator for sin(70∘):
sin(70∘)≈0.939692621
A△OAB=98×0.939692621
A△OAB≈92.109876858cm2
Step 5: Calculate the area of the minor segment.
The area of the minor segment is the area of the sector OAB minus the area of the triangle OAB.
Asegment=Asector−A△OAB
Asegment=91078−98sin(70∘)
Asegment≈119.777777...−92.109876858
Asegment≈27.667900142cm2
Rounding to three decimal places:
Asegment≈27.668cm2
The area of the minor segment is 27.668cm2.