Answer:
3) Area of sector is

4) The length of arc of semicircle is 22 cm.
Explanation:
Question 3.
Given
angle subtended by arc Φ = 129°
radius = 5 cm
We need to find the Area of the sector.
Solution:
Area of the sector is equal to Angle divided by 360 multiplied by π multiplied by square of the radius
framing in equation form we get;
Area of the sector =

Hence Area of sector is

Question 4.
Given:
radius = 7 cm
angle subtended by arc Φ = 180°
We need to find the arc length of the semicircle.
Solution,
Length of arc is equal to Angle divided by 360 multiplied by 2 times π multiplied by radius.
framing in equation form we get;
Length of arc =

Hence The length of arc of semicircle is 22 cm.