Tag: bearing and drawings

Quizzes (1) Questions (40)

Questions Related to bearing and drawings

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

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.

  1. 6.75 cm

  2. 5.75 cm

  3. 6.25 cm

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

$\triangle LMN$ is reduced to $\triangle L'M'N'$,
Thus, $\dfrac{L'M'}{LM} = 0.8$
$\Rightarrow \dfrac{5.4}{LM} = 0.8$
$\Rightarrow LM = \dfrac{5.4}{0.8}$
$\Rightarrow LM = 6.75$ 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 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.

  1. 6.4 cm

  2. 4.4 cm

  3. 5.4 cm

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

$\triangle LMN$ is reduced to $\triangle L'M'N'$,
Thus, $\dfrac{M'N'}{MN} = 0.8$
$\Rightarrow \dfrac{M'N'}{8} = 0.8$
$\Rightarrow M'N' = 0.8 \times 8$
$\Rightarrow M'N' = 6.4 $ 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 BC. if B'C'= 15 cm.

  1. 6 cm

  2. 5 cm

  3. 7 cm

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

$\triangle ABC$ is enlarged to $\triangle A'B'C'$,
Thus, $\dfrac{B'C'}{BC} = 3$
$\Rightarrow \dfrac{B'C'}{BC} = 3$
$\Rightarrow BC = \dfrac{15}{3}$
$\Rightarrow BC = 5$ cm 

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

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 ? 

  1. $S _1$ is true, but $S _2$ is not true.
  2. $S _2$ is true, but $S _1$ is not true.
  3. Both $S _1$ and $S _2$ are true
  4. Neither $S _1$ and $S _2$ are true
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

For similarity of triangles we have SSS criteria. So $S _1$ is true. 
But for polygons to be similar, the corresponding sides must be in equal ratio as well as the corresponding angles must be congruent.

Since, there is nothing mentioned about the angles of the pentagons, so $S _2$ is false.

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 A'B', if AB = 4cm.

  1. 12 cm

  2. 14 cm

  3. 22 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, $\dfrac{A'B'}{AB} = 3$
$\Rightarrow \dfrac{A'B'}{4} = 3$
$\rightarrow A'B' = 4 \times 3$
$\Rightarrow A'B' = 12 $ 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 OC', if  OC=21 cm.

  1. 63 cm

  2. 53 cm

  3. 43 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, $\dfrac{OC'}{OC} = 3$
$\Rightarrow \dfrac{OC'}{21} = 3$
$\Rightarrow OC' = 21 \times 3$
$\Rightarrow OC' = 63 $ cm

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

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:

  1. $10$ m
  2. $12.5$ m
  3. $17.5$ m
  4. $21.25$ m
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Flagstaff and shade forms right triangle with height $17.5$ m and base $40.25$ m

$\dfrac{17.5}{40.25} = \tan(\theta)$
under similar conditions $\theta$ will remain same.
Lets assume height of the building as $H$
Hence, $ \tan(\theta)=\dfrac{17.5}{40.25}$ $ = \dfrac {H}{20.75}$
$\Rightarrow  H= 12.5$ m

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

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):

  1. 2

  2. 2.5

  3. 7

  4. 10

  5. 12.5
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Ratio of the length of the sides of the two triangle $=2:5$

If hypotenuse  of small triangle $=5$ inches
Let the hypotenuse of  larger triangle $=x$
$\therefore \dfrac{5}{x}=\dfrac{2}{5}$
$\therefore  x=\dfrac{25}{2}=12.5$  inches

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

If the image of an object is enlarged, then what would be the effect on scale factor, $k?$

  1. $k$ will remain same for both.
  2. $k>1$ for enlarged image.
  3. $k<1$ for enlarged image.

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


If image is enlarged, $k>1.$
If image size does not change, then $k=1.$
If image size is reduced, $k<1.$