Sarin learns Perimeter, Area and Volume in school part 108 (Math Question)

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The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presents the Math Concept, the Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can acquire the skill of dealing with the Math Modeling, the Math Problem Solving and the Problem Sum from Lower Primary School to Upper Primary School level after reading the blog postings. This posting is an upper primary school math question on Shape and Area

You can read posting Sarin learns Perimeter, Area and Volume in school (Math Concept) to learn the concept of area.

Read also the posting on Sarin learns Shapes and Solids in school (Math Concept) to know about shapes.

Challenge yourself with the question before look out for the given solution‼!

Upper primary school mathematics question UPQ506

The figure below, not drawn to scale, is made up of 4 identical circles and an equilateral triangle touching the points A, B and C on the circles. If the area of the triangle is 81 cm2 and the diameter of the circle is 16 cm, find the area of the blue region. (π = 3.14) Express your answer correct to 2 decimal places.

UPQ506-1

Solution:

UPQ506-2

The radius of the circle = 16 ÷ 2 = 8 cm

1/6 of the area of one circle = 1/6 × π × 8 × 8 = 32π/3 cm2

The area of the yellow triangle is 1/3 of triangle ABC

1/3 of the area of the triangle ABC = 81 ÷ 3 = 27 cm2

1/2 of the area of the blue region = (32π/3 – 27) = 6.49 cm2

The area of the blue region = 2 × 6.49 = 12.99 cm2

   More Questions on Area. Click here….

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