Every year, the PSLE includes a few challenging math questions designed to test problem-solving skills, and 2025 is no exception. This PSLE Math 2025 question has pushed even the most confident learners to think critically. The problem involves a figure made up of three identical equilateral triangles:
How to Solve this PSLE Math 2025 Question?
The figure below is made up of 3 identical equilateral triangles.
(a) Find the length of AB.
(b) Find the perimeter of the shaded parts.
Many students have called this the most difficult question in PSLE Math 2025. To solve it, a self-motivated learner must pick up key clues. Recognising that all triangles are identical and equilateral establishes that all sides are equal. Understanding that the overlapping parts of the triangles are also of equal length allows the length of AB to be determined. From there, calculating the perimeter of the shaded areas becomes straightforward.
This problem shows why confident learners benefit from instant homework help or on-demand homework help. Step-by-step solutions help students tackle the toughest PSLE Math 2025 questions with strategy, skill and confidence.
K16
- Hi
- Hello!
- How can I help you today?
- can u help me with this qn?
- Sure
- The 3 triangles are equilateral triangles, find length AB
- Any other information to share?
- no
- Ok, let me take a look at this question.
- Oh, this is a tricky question. Let me guide you step-by-step.
- ok
- Refer to the diagram below instead
- so, to make the explanation easier
- I have labelled all the points on the triangle.
- ok
- For a start
- Let's compare AC and DG
- Let's compare AC and DH
- What can you tell from these 2 length?
- they are equal?
- Actually the 2 lengths are equal.
- Yes, you are right.
- But why are they equal?
- You can see that CD is the part that is overlapping
- So this tells us that DH = 18 cm as well :)
- so like if u flip the triangle DH is like AC
- Yes! That's right!
- Next, we need to find the length HJ
- I highlighted it in orange
- so is just 41-18?
- Yes! That's correct.
So we find the length of HJ, which is 23 cm. 
- From the information we found, i have updated the image here :)
- ohhh i got it
- Do you know how to find the length of AB?
- AB = GJ = 23+3 = 26cm
- right?
- Well done!
- yay!
- That's the correct answer :)
- i have another qn with the same diagram tho
- ?
- can u help?
- What's your question?
- i need to find the perimeter of the shaded areas
- That's easy. You might not need my help on that ;)
- Let me give you a clue
- Find the length of CD
- Since it is an equilateral triangle
- 26-18?
- Bingo!
- That's 6 cm
- 8 cm
- Not 6 cm, my bad on that :)
- but CE is also 8?
- or the small triangles are not equal?
- yes, CE is also 8 cm
- the small triangles are also equilateral triangles
- oh
- Look at this diagram here
- i got it
- Add up the sides of the shaded parts and you should get the answer :)
- What's your answer?
- Did you get 145 cm?
- yes
- Well done!
- Hope I managed to help you understand how to solve the question
- I will see you around
- Goodbye!!
- thank you
- byebye
