10 questions · Form 5 Mathematics Bab 5: Congruency, Enlargement and Combined Transformations
What is a pattern called when repeated geometric shapes cover a surface completely without gaps or overlaps?
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. What is a pattern called when repeated geometric shapes cover a surface completely without gaps or overlaps?
Answer: A
A tessellation is a tiling pattern made of repeating shapes covering a plane without gaps or overlaps.
2. If a transformation maps a shape onto an image such that orientation is reversed but size and shape remain unchanged, the transformation is a...
Answer: B
Reflection preserves distance and shape (isometry) but reverses the orientation (lateral inversion) of the shape.
3. A shape with an area of 25 cm² is enlarged to an image with an area of 4 cm². What is the scale factor k (where k > 0)?
Answer: B
k² = Area of Image / Area of Object = 425. Thus, k = √(425) = 25 = 0.4.
4. An object has an area of 15 cm². It is enlarged with a scale factor of k = -3. What is the area of the resulting image?
Answer: A
Area of Image = k² × Area of Object = (-3)² × 15 = 9 × 15 = 135 cm². (Area is always positive).
5. Why does the criterion Angle-Angle-Angle (AAA) NOT prove that two triangles are congruent?
Answer: A
AAA guarantees that two triangles have the same shape (similar), but their sizes can differ, so they are not necessarily congruent.
6. What does a negative scale factor (e.g., k = -2) indicate about the image under an enlargement?
Answer: A
A negative scale factor produces an inverted image on the opposite side of the center of enlargement.
7. Which of the following transformations is NOT an isometry?
Answer: A
Enlargement changes the size of the shape (unless k = 1), so it is not an isometry. Translation, reflection, and rotation preserve both shape and size.
8. If an object with a side length of 6 cm is enlarged with a scale factor of k = 3, what is the side length of the image?
Answer: A
Image Side Length = |k| × Object Side Length = 3 × 6 cm = 18 cm.
9. If triangle ABC is congruent to triangle DEF, which statement must be true?
Answer: A
Congruent shapes are identical in both shape and size; all corresponding angles and sides are equal.
10. Triangle PQR undergoes a rotation of 90° clockwise about the origin. If P is at (3, 1), what are the coordinates of its image P'?
Answer: A
A 90° clockwise rotation about the origin transforms (x, y) into (y, -x). Thus, (3, 1) becomes (1, -3).