the perimeter and the area of the shaded region in the following figure all the measurements are in centimetre
Answers
Given :-
- Here, we have figure maded by joining semicircle and rectangle.
- Length of rectangle is 10.5 units and it's width is 4 units.
To Find :-
- Perimeter and area of figure.
Solution :-
Firstly, finding perimeter of the figure :-
- Diameter (D) of semicircle = 10.5 – 3.5
[ Because whole length is 10.5 units and length upto first end of diameter is 3.5 units. So, we will subtract 3.5 from 10.5, to get diameter of semicircle ]
➱ㅤㅤㅤD = 10.5 – 3.5
➱ㅤㅤㅤD = 7
∴ Diameter of semicircle is 7 units
So, it's radius = 7/2 units
❂ [Perimeter of semicircle = πr] ❂
Putting all values :-
➱ㅤㅤㅤ22/7 × 7/2
➱ㅤㅤㅤ(22 × 7)/(7 × 2)
➱ㅤㅤㅤ22/2
➱ㅤㅤㅤ[ 11 ] ★
∴ Perimeter of semicircle is 11 units
But we need measure of only curved side
So, we will subtract it's diameter from perimeter
➱ㅤㅤㅤ11 – 7
➱ㅤㅤㅤ[ 4 ] ★ㅤㅤㅤ– – – – – – [1]
Now,
[Perimeter of rectangle = Sum of all sides]
But here we need measure upto ends of diameter only, therefore we will subtract 7 from it's perimeter.
Putting all values :-
➱ㅤㅤㅤ10.5 + 4 + 10.5 + 4 – 7
➱ㅤㅤㅤ29 – 7
➱ㅤㅤㅤ[ 22 ] ★ㅤㅤㅤ– – – – – – [2]
★ To get perimeter of whole figure we will add [1] and [2] :-
➱ㅤㅤㅤ4 + 22
➱ㅤㅤㅤ[ 26 ] ★
∴ Perimeter of given figure is 26 units
Now, finding it's area :-
[It's area = area of rectangle + area of semicircle]
✴ Solving :-
➱ㅤㅤ[ l × w ] + [ πr² ÷ 2 ]
➱ㅤㅤ[10.5 × 4] + [(22/7 × 7/2 × 7/2) ÷ 2]
➱ㅤㅤ42 + (38.5 ÷ 2)
➱ㅤㅤ42 + 19.25
➱ㅤㅤ[ 61.25 ] ★
∴ Area of given figure = 61.25 sq.units
- Perimeter of fig = 26 units
- Area of fig = 61.25 sq.units
ㅤㅤㅤ✴ Hence Solved ✴
Answer:
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Step-by-step explanation:
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