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primary 6 | Maths | Measurement
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Elly
Elly

primary 6 chevron_right Maths chevron_right Measurement chevron_right Singapore

Elp

Date Posted: 5 years ago
Views: 308
J
J
5 years ago
AE = EC = 2 radii of circle = 1 diameter
= 6cm

Triangle ABD and BCD are identical halves of the rhombus. They have the same lengths for the sides (rhombus' sides are equal) and they share a common side BD

So Area of rhombus
= 2 x area of triangle ABD
= 2 x AE x BD
= 2 x ½ x 6 cm x 20.8 cm
= 124.8 cm²


In the rhombus, there's :
●1 full unshaded circle
● 4 unshaded semicircles,
(the rhombus sides passes through their centre)
● 4 circle sectors


The 4 circle sectors have a combined angle of 360°(since their angles are made up of all angles of the rhombus)

Since a full circle has an angle of 360°, the 4 sectors inside add up to 1 full circle.

4 unshaded semicircles equal area of 2 unshaded circles.

Total area unshaded inside rhombus
= 1 + 1 + 2 = 4 unshaded circles.


Radius of a circle = 6cm ÷ 2 = 3cm

Shaded area
= rhombus area - 4 unshaded circles area
= 124.8cm² - 4 x 3.14 x 3cm x 3cm
= 124.8cm² - 113.04cm²
= 11.76cm²

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AC Lim
Ac Lim's answer
13088 answers (A Helpful Person)
1st
Hope this helps
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sstrike
Sstrike's answer
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