Sail E0 Webinar

9th Grade > Mathematics

CONSTRUCTIONS MCQs

Total Questions : 56 | Page 2 of 6 pages
Question 11. If AE = BE, then CD is the perpendicular bisector of line segment AB.
If AE = BE, Then CD Is The Perpendicular Bisector Of Line Se...
  1.    True
  2.    False
  3.    Median
  4.    Altitude
 Discuss Question
Answer: Option B. -> False
:
B
Theperpendicular bisectoris a line that divides a line segment into two equal parts andalso makes a right angle with the line segment. Here CD divides AB into two equal parts but is not perpendicularto it. Hence it is not a perpendicular bisector.
Question 12. With a ruler and compass which of the following angles cannot be constructed?
  1.    80∘
  2.    60∘
  3.     90∘
  4.    105∘
 Discuss Question
Answer: Option A. -> 80∘
:
A
With a ruler and compass we can construct 15,30,45,60, 90,105angles. We cannot construct80.
Question 13. Which of the following figures show the correct method to construct a triangle if we know its base, a base angle and sum of other two sides?
 Discuss Question
Answer: Option A. -> 80∘
:
A
The correct procedure to construct the given triangle is:
1. Draw the base BC of Δ ABC as given and construct XBC of the required measure at B as shown.
Which Of The Following Figures Show The Correct Method To Co...
2. Keeping the compass at point B cut an arc from the ray BX such that its lengthequals to AB + AC at point P and join it to C as shown.
Which Of The Following Figures Show The Correct Method To Co...
3. Now measure BPC and from C draw an angle equal to BPC as shown.
Which Of The Following Figures Show The Correct Method To Co...
Thus, option A is correct.
Question 14. A 75 angle can be made by drawing angle bisector between a 90 angle arm and a ___ angle arm.
 Discuss Question

:
75=90+602
Hence bisecting 90 and 60will give 75.
Question 15. We can draw a triangle if we know its perimeter and one base angle.
  1.    True
  2.    False
  3.    Not always
  4.    Cannot be predicted
 Discuss Question
Answer: Option B. -> False
:
B
To draw a triangle,we must know its perimeter along with twobase angles. Hence the given statement is false.
Question 16. For making an angle of 105, you need to construct a 60 angle too.
  1.    True
  2.    False
  3.    Draw perpendicular bisector of AD
  4.    Draw angle bisector of  ∠ A
 Discuss Question
Answer: Option A. -> True
:
A
A105 angle can be constructed by drawing a bisector between 120 angle arm and 90 arm as shown in the figure below. But it can be seen clearly that for making 120 and 90 angles, one needs to make a 60 angle first. In the image given, DAB will be 60 .
For Making An Angle Of 105∘, You Need To Construct A 60∘...
Question 17. In the figure shown below, ABD = DBC, then  the ray BD is called
In The Figure Shown Below, ∠ABD = ∠DBC, Then  The Ray B...
  1.    Angle bisector
  2.    Perpendicular bisector
  3.    Median
  4.    Altitude
 Discuss Question
Answer: Option A. -> Angle bisector
:
A
An angle bisector divides a given angle into two equal angles. Since BD divides ABC into two equal angles, it is an angle bisector.
Question 18. The steps to draw a triangle with the base BC, a base angle B and the difference of other two sides is given below.
1. Draw the base BC and at point B make an angle say XBC equal to the given angle.
2. Cut the line segment BD equal to AB - AC on the reflection of ray BX (i.e. BX').
3. Join DC and draw the perpendicular bisector, say PQ of DC.
​​
The next step will be:
  1.    Let PQ intersect BX at a point A. Join AC.
  2.    Draw angle bisector of ∠C
  3.    Draw perpendicular bisector of AD
  4.    Draw angle bisector of  ∠ A
 Discuss Question
Answer: Option A. -> Let PQ intersect BX at a point A. Join AC.
:
A
The next step is:
4. Let PQ intersect BX at a point A. Join AC. Δ ABC is the required triangle. The construction is shown in the image below.

The Steps To Draw A Triangle With The Base BC, A Base Angle ...
Question 19. Given an angle of 60, it is possible to get 30.
  1.    True
  2.    False
  3.    Draw perpendicular bisector of AD
  4.    Draw angle bisector of  ∠ A
 Discuss Question
Answer: Option A. -> True
:
A
It is possible to get 30from given angle of 60by simply drawing an angle bisector. Hence the given statement is true.
Question 20. In the given construction of a ΔABC, CAB will be
In The Given Construction Of A ΔABC, ∠CAB Will Be
  1.    55∘
  2.    45∘
  3.    75∘
  4.    60∘
 Discuss Question
Answer: Option B. -> 45∘
:
B
In The Given Construction Of A ΔABC, ∠CAB Will Be
In ΔAXB
PQ is the perpendicular bisector ofXA, the two triangles formed are congruentby SASrule.
AB = XB
BAX=AXB
ABC=BAX+AXB
= 2AXB=LXY
[Since AXB is angle bisector of LXY]
Similarly,ACB=MYXTherefore,ABC=75andBCA=60InΔABC,wehaveABC+BCA+CAB=18075+60+CAB=180CAB=180135CAB=45

Latest Videos

Latest Test Papers