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 UPQ508
The figure below, not drawn to scale is made up of a rectangle ABCD and a semicircle. E and F are mid-points of AB and DC respectively. The length of DC is 20 cm. EO is ½ of EF. Find the total area of the yellow region of the figure. (Take π = 3.14)
DECFD is a semicircle and F is the mid point of DC
DF = FC = 10 cm
The area of the quarter DEOFD = ¼ × π × 10 × 10 = 25π cm2
O is mid point of EF
OF = 10 ÷ 2 = 5 cm
The area of the triangle OCF = ½ × 10 × 5 = 25 cm2
The area of the unshaded region = 20 × 10 – 25 – 25π = 96.5 cm2