Tag: enlargement

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Questions Related to enlargement

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

A rectangle of length $4\ cm$ and breadth $3\ cm$ is scaled up $2$ times. What is the new length of the rectangle?

  1. $6\ cm$
  2. $4\ cm$
  3. $8\ cm$
  4. $3\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The size of the rectangle become double when it is scaled up $2$ times.

So new length $=2\times 4=8\ \ cm$
So option $C$ is correct.

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

A circle of radius $7\ cm$ is scaled $3$ times. Then the perimeter of the circle become:

  1. $3$ times the original perimeter
  2. $6$ times the original perimeter
  3. $9$ times the original perimeter

  4. Doesn't change
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Radius of circle $=7 \ \ cm$

Perimeter $=2\pi r=2\times \pi\times7=14\pi\ \ cm$
When scaled $3$ times
New radius $=3\times 7=21 \ \ cm$
New Perimeter $=2\pi r=2\times \pi\times21=42\pi\ \ cm$
Ratio of perimeters $=\dfrac{42\pi}{14\pi}=3$
So the perimeter becomes three times.

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

If one shape becomes another using rotation / reflection, then the shapes are __________.

  1. similar

  2. congruent

  3. mirror images

  4. none of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If the size of the figure does not get affected by rotation or reflection, then the figure will remain same and it will be congruent.

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

If the area of square is $36\pi \ \text{cm}^2$. If its length is scaled three times, what would be its new area?

  1. $342\pi$
  2. $324\pi$
  3. $352\pi$
  4. $322\pi$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Area of square whose side is $a =a^2$ 

If its length is scaled three times, then area $=9a^2$
Therefore, new area $=9\times 36\pi \text{cm}^2=324\pi \text{cm}^2$

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

The measure of $3.4\ cm$ on a $2:1$ scaled model will be:

  1. $3.4\ cm$
  2. $6.8\ cm$
  3. $1.7\ cm$
  4. $4.5\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let orignal length $=l$ and scales length $=sl$

$\dfrac { l }{ sl } =\dfrac { 2 }{ 1 } \ \dfrac { 3.4 }{ sl } =\dfrac { 2 }{ 1 } \ \Rightarrow sl=1.7$
So option $C$ is correct.

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

A $30-60-90$ degree triangle is scaled $1.5$ times. The new angles of the triangle are:

  1. $45-45-90$
  2. $30-60-90$
  3. $37-53-90$
  4. $60-60-60$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When the triangle is scaled $1.5$ times then length of each side become $1.5$ times but the angle remains the same.

So the new angles are $30-60-90$
Option $B$ is correct.

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

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?

  1. $100\ cm$
  2. $500\ m$
  3. $100\ m$
  4. $500\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
$L = OriginalLength$
$l=ScaledDownLength= 100cm = 1m$

$\cfrac{l}{L}= \cfrac{1}{100}$
$\cfrac{1m}{L} = \cfrac{1}{100}$
$L= 100m$


Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

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.

  1. 10

  2. 8

  3. 6

  4. 12
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\triangle ABC$ is enlarged to $\triangle A'B'C'$,
Thus, $\dfrac{C'A'}{CA} = 2.5$
Therefore, $\dfrac{C'A'}{4} = 2.5$
$\Rightarrow C'A' = 4 \times 2.5$
$\Rightarrow C'A' = 10$ cm 

Multiple choice maths enlargement and scale drawing dilation enlargement similarity as a size transformation mapping mapping space around us bearing and drawings

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.

  1. 2 cm

  2. 3 cm

  3. 4 cm

  4. none of the above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\triangle ABC$ is enlarged to $\triangle A'B'C'$,
Thus, $\dfrac{OA'}{OA} = 3$
$\Rightarrow \dfrac{6}{OA} = 3$
$\Rightarrow OA = \dfrac{6}{3}$
$\Rightarrow OA = 2 $ cm