Enlargement and scale drawing - class-X
enlargement and scale drawing
Questions
A rectangle of length $4\ cm$ and breadth $3\ cm$ is scaled up $2$ times. What is the new length of the rectangle?
- $6\ cm$
- $4\ cm$
- $8\ cm$
- $3\ cm$
A circle of radius $7\ cm$ is scaled $3$ times. Then the perimeter of the circle become:
- $3$ times the original perimeter
- $6$ times the original perimeter
- $9$ times the original perimeter
- Doesn't change
If one shape becomes another using a resize, then the shapes are __________.
- similar
- congruent
- mirror images
- none of the above
If one shape becomes another using rotation / reflection, then the shapes are __________.
- similar
- congruent
- mirror images
- none of the above
If the area of square is $36\pi \ \text{cm}^2$. If its length is scaled three times, what would be its new area?
- $342\pi$
- $324\pi$
- $352\pi$
- $322\pi$
The measure of $3.4\ cm$ on a $2:1$ scaled model will be:
- $3.4\ cm$
- $6.8\ cm$
- $1.7\ cm$
- $4.5\ cm$
A $30-60-90$ degree triangle is scaled $1.5$ times. The new angles of the triangle are:
- $45-45-90$
- $30-60-90$
- $37-53-90$
- $60-60-60$
A submarine is scaled down to $\dfrac{1}{100}$ times for making a model. If the length of the submarine in the scaled down model was $100\ cm$, what is the original length of the submarine?
- $100\ cm$
- $500\ m$
- $100\ m$
- $500\ cm$
A triangle ABC has been enlarged by scale factor m= 2.5 to the triangle A' B' C'. Calculate the length of C' A' if CA=4 cm.
- 10
- 8
- 6
- 12
A triangle ABC is enlarged, about the point O as centre of enlargement, and the scale factor is 3. Find OA, if OA'= 6 cm.
- <span>2 cm</span>
- <span>3 cm</span>
- <span>4 cm</span>
- none of the above
A triangle LMN has been reduced by scale factor 0.8 to the triangle L' M' N'. Calculate the length of LM, if L' M'= 5.4 cm.
- <span>6.75 cm</span>
- <span>5.75 cm</span>
- <span>6.25 cm</span>
- none of the above
A triangle LMN has been reduced by scale factor 0.8 to the triangle L' M' N'. Calculate the length of M' N'. if MN= 8 cm.
- <span>6.4 cm</span>
- <span>4.4 cm</span>
- <span>5.4 cm</span>
- none of the above
A triangle ABC is enlarged, about the point O as centre of enlargement, and the scale factor is 3. Find BC. if B'C'= 15 cm.
- <span>6 cm</span>
- <span>5 cm</span>
- <span>7 cm</span>
- none of the above
A has a pair of triangles with corresponding sides proportional, and B has a pair of pentagons with corresponding sides proportional.
$S _1 \equiv $ A's triangles must be similar
$S _2 \equiv $ B's pentagons must be similar
Which of the following statement is correct ?
- $S _1$ is true, but $S _2$ is not true.
- $S _2$ is true, but $S _1$ is not true.
- Both $S _1$ and $S _2$ are true
- Neither $S _1$ and $S _2$ are true
A triangle ABC is enlarged, about the point O as centre of enlargement, and the scale factor is 3. Find A'B', if AB = 4cm.
- <span>12 cm</span>
- <span>14 cm</span>
- <span>22 cm</span>
- none of the above
A triangle ABC is enlarged, about the point O as centre of enlargement, and the scale factor is 3. Find OC', if OC=21 cm.
- <span>63 cm</span>
- <span>53 cm</span>
- <span>43 cm</span>
- none of the above
A flagstaff $17.5$ m high casts a shaded length of $40.25$ m. The height of the building which costs a shadow of length $28.75$ m under similar conditions will be:
- $10$ m
- $12.5$ m
- $17.5$ m
- $21.25$ m
The ratio of the lengths of the corresponding sides of $2$ similar right angled triangles is $2:5$. If the length of the hypotenuse of the smaller triangle is $5$ inches, find the length of the hypotenuse of the larger triangle (in inches):
- 2
- 2.5
- 7
- 10
- 12.5
If the image of an object is enlarged, then what would be the effect on scale factor, $k?$
- $k$ will remain same for both.
- <span>$k>1$ </span>for enlarged image.
- <span>$k<1$</span> for enlarged image.
- none of the above