# Sarin learns Perimeter, Area and Volume in school part 55 (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 presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn deal with Math Modeling, Problem Sum from Lower Primary School to Upper Primary School level. This posting is an upper primary school math question on Perimater and Area.

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

Read also the posting on Sarin learns the concept of Fraction (mathematics concept) to understand the concept of Fraction.

Upper primary school mathematics question UPQ221

The figure below is made up of 5 circles with the same radius 10cm. V, W, X, Y and Z are the centres of the circles respectively. For each of the following, use the calculator value of π to find

(a) the perimeter of the orange shapes, correct to 2 decimal places;

(b) the area of the orange shapes, correct to 2 decimal places.

Solution:

Refer to the Purple lines link the centre points X, Y , Z

The circumference length from X to Z clockwise = 1/3 fraction of the full circle

Similarly, the area of the circle underneath = 1/3 fraction of the full circle

The perimeter of the orange shapes = 4/3 × π × 2 × 10 × 2 = 167.55 cm

The area of the orange shapes = 2/3 × π × 10 × 10 × 2 = 418.88 cm2