iGCSE Mathematics (0580) - C4.4 Similarity- Exam Style Questions Paper 1- New Syllabus
Question

Rectangle $A$ is mathematically similar to rectangle $B$.
Work out the value of $x$.
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
Since the rectangles are mathematically similar, the ratio of their corresponding sides is exactly the same. We can find the linear scale factor from rectangle $B$ to rectangle $A$: $$\text{Scale Factor} = \frac{\text{Length of } A}{\text{Length of } B} = \frac{8}{2} = 4$$ This means rectangle $A$ is 4 times larger in every dimension. We apply this factor to the width: $$x = 1.5 \times 4 = 6$$
Answer: $x =$ 6
Question

Triangle $ABC$ is mathematically similar to triangle $PQR$. Given $AB=5\text{ cm}$, $BC=7\text{ cm}$, and $PQ=10\text{ cm}$, show that $QR = 14\text{ cm}$.
Most-appropriate topic codes (Cambridge IGCSE Mathematics 0580):
▶️ Answer/Explanation
✅ Answer: $\frac{10}{5} \times 7 = 14$

Shape A is mathematically similar to shape B.
Calculate the value of x.
▶️ Answer/Explanation
Ans: 8 cm
Find the scale factor: 6.75 ÷ 2.7 = 2.5
Apply to the other side: x = 3.2 × 2.5
Calculate: x = 8 cm
Alternatively: 3.2/x = 2.7/6.75 → x = (3.2 × 6.75)/2.7 = 8
