area and perimeter of semi-circles and can anyone help me answer this exam style question.?

Question

can anyone explain to me how i would find the area and also perimeter of a semi circle or half circle please.

Also can anyone help me answer this gcse maths exam style question please:

The diameter of the semi circle is 8cm. work out the perimeter of the tile.
give your answer correct to 2 decimal places.

many thanks

Answer 1

You said "work out the perimeter of the tile", so the question is about the perimeter of a semicircular tile, is that correct? If so, then I don't think Will H's answer is right. His calculation of the curved section is correct, but you would need to add 8 cm, for the straight edge. You should clarify this with your teacher.

Answer 2

area of a semicircle= half of the area of a circle

ie area of semi-circle=1/2 × π × r2

perimeter of a semicircle (also called circumference) = half of a that of a circle

ie perimeter of a semicircle=1/2 × 2π × r



for your question we need to know if the semicircle is placed inside the tile. [im considering it is]

if it is, than the diameter of the circle is equal to the length of the tile therefore being 8cm. the parallel side would also be 8 cm.

now to know the height, we half the diameter since the hight of the tile is the radius of the semicircle

so 1/2 x 8 = 4cm

to get the perimeter,add all the sides, 8+8+4+4=24cm

Answer 3

Area Circle = пr²

Area Semi-Circle = пr²/2

Perimeter Circle = 2пr or пd

Perimeter Semi-Circle = пr or пd/2



If d = 8cm

Perimeter Semi-Circle = пd/2

= 4п cm

= 12.57cm

Answer 4

Do you know how to find the area and perimeter of a circle?

Answer 5

we want 0.5 the fringe of a circle, plus the diameter. Perimeter of a Circle: 2?r Diameter of a Circle = 2r So we want 0.5 the fringe of the circle: .5(2?(.5(28))) = ?(14) Plus the diameter: ?(14) + 28

Answer 6

= 8 + 4(22/7)

= (56 + 88)/7

= 144/7 or 20 4/7



Answer: 20.57 cm is the perimeter

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= (22/7[8/2]²)/2

= (22/7[4]²)/2

= (22/7[16])/2

= 352/14 or 176/7

= 25 1/7



Answer: 25.14 sq cm is the area.

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