PSLE 2023 Circle and Trapezium Math Questions
In this revision note, we will go through PSLE 2023 Circle and Trapezium questions so that your child will become better at solving area and perimeter questions.
These questions assess your child’s agility in visualizing and fitting various shapes.
Before you read on, you might want to download this entire revision notes in PDF format to print it out for your child, or to read it later.
This will be delivered to your email inbox.
PSLE 2023 Math Circle Question
Each circle has a radius of 7 cm.
a) Find the perimeter of the shaded part.
b) Find the area of the shaded part.
Take π as 22/7.
Solutions
a) Perimeter = the total lengths outside the shaded part
Let’s break up the perimeter into 3 parts.
Observe that each part is the circumference of a circle.
3/4 Circle + 1/4 Circle
= 1 circle
Diameter of circle = 7 x 2 = 14 cm
The perimeter of the shaded part
= Circumference of 3 circles
= π × d × 3
= 22/7 × 14 × 3
= 132 cm (Ans)
b) To find the area, we can use the cut-and-paste method:
Shaded area
= the rectangle + ½ circle + ½ circle
= 1 rectangle + 1 circle
Length of rectangle = 7 cm x 4
= 28 cm
Breadth of rectangle = 7 cm x 2
= 14 cm
Area of rectangle = 28 cm x 14 cm
= 392 cm2
Area of circle = 22/7 x 7 x 7
= 154 cm2
Shaded area = 392 cm2 + 154 cm2
= 546 cm2 (Ans)
PSLE 2023 Math Trapezium Question
The figure shows a trapezium with a perimeter of 96 cm.
a) Figure A is made up of 3 such trapeziums and has a perimeter of 204 cm.
Find the length of PQ.
b) Figure B is made up of 4 such trapeziums and has an area of 1932 cm2. Given that CD = 12 cm, find the length of PS.
Solutions
a) Breaking Figure A into the 3 trapeziums, we see that 4 PQs (highlighted in yellow) are not counted in the perimeter of Figure A.
Hence,
Perimeter of Figure A = Perimeter of 3 Trapeziums – 4 PQ
Perimeter of 3 Trapeziums = 3 x 96 cm = 288 cm
Perimeter of Figure A = Perimeter of 3 Trapeziums – 4 PQ
204 cm = 288 cm – 4 PQ
4 PQ = 288 cm – 204 cm = 84 cm
PQ = 84 cm ÷ 4 = 21 cm (Ans)
b) Observe that 2 trapeziums can form a rectangle in Figure B.
Area of 4 trapeziums = 1932 cm2
Area of 2 trapeziums = 1932 cm2 ÷ 2
= 966 cm2
Area of rectangle = 966 cm2
Breadth of rectangle = PQ = 21 cm (from part a)
Length of rectangle = Area of rectangle ÷ Breadth
= 966 cm2 ÷ 21 cm
= 46 cm
PS is the shorter parallel side of the trapezium.
PS = 46 – 12 – 21 = 13 cm (Ans)
Test your child’s understanding by taking this short quiz!
Click the button below.
Before you go, you might want to download this entire revision notes in PDF format to print it out for your child, or to read it later.
This will be delivered to your email inbox.
Does your child need help in his or her studies?
1) Live Zoom Lessons at Grade Solution Learning Centre
At Grade Solution Learning Centre, we are a team of dedicated educators whose mission is to guide your child to academic success. Here are the services we provide:
– Live Zoom lessons
– Adaptably™, an innovative smart learning platform featuring thousands of PSLE and exam-based questions tailored for your child’s practice. Adaptably not only tracks your child’s progress but also identifies their strengths and areas for improvement, providing valuable insights to enhance their learning journey.
– 24/7 Homework Helper Service
We provide all these services above at a very affordable monthly fee to allow as many students as possible to access such learning opportunities.
We specialise in English, Math, Science and Chinese subjects.
You can see our fees and schedules here >>
2) Pre-recorded Online courses on Jimmymaths.com
If you are looking for something that fits your budget, or prefer your child learn at his or her own pace, you can join our pre-recorded online Math courses.
Your child can:
– Learn from recorded videos
– Get access to lots of common exam questions to ensure sufficient practice
– Get unlimited support and homework help
You can see the available courses here >>