Elitmus
Exam
Numerical Ability
Geometry
Q. The angles of 2 sides of quadrilateral B and D are 90 degree each. BP and DQ are perpendicular to diagonal AC and it trisects the AC(AP=PQ=QC). Side AB is 4cm then find perimeter of quadrilateral.
Read Solution (Total 8)
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- B,D are 90 so its a rectangle
let AD=X then AC^2=(16+X^2) AP=AC/3
SO AP^2=AC^2/9=(16+X^2)/9
BP^2=AB^2-AP^2=16-{(16+X^2)/9}
equate area of triangle ABC
(1/2)*AC*BP = (1/2)*AB*BC
or AC^2*BP^2 = AB^2*BC^2
or (16+x^2)*[16-{(16+X^2)/9}]=16*x^2
after solving
x^4+32x^2-32*64=0
x^2= 32 or -64
x^2=32
so x=4*(sqrt 2)
perimeter of quadrilateral=2(x+4)
=2[4*(sqrt 2)+4]
=8(1+sqrt(2)) - 11 years agoHelpfull: Yes(16) No(8)
- https://fbcdn-sphotos-e-a.akamaihd.net/hphotos-ak-frc3/1476375_268402199980030_2069894024_n.jpg THIS IS THE IMAGE OF DIAGRAM ..
- 10 years agoHelpfull: Yes(8) No(2)
- Rakesh could you please provide the diagram....please
- 11 years agoHelpfull: Yes(4) No(0)
______________ _
A| / |D
| p / |
| / Q/ |
B|/___________ __|C
BP_|_AC
DQ_|_AC
AB_|_BC
DC_|_AD
so right angle traingles are ABC,DAC,ABP,DQC,BPC,ADQ...but we just need 3 of them
take ABC, ABP & BPC
AB=DC=4;
Let AD=BC=x;
Let AP=a;
so AC=3a;
from |_ ABC
x^2-16=9a^2; ---------(1)
from |_ ABP
BP^2=16-a^2 ---------(2)
from |_ BPC
16-a^2=x^2-4a^2 (use 2)
3a^2=x^2-16 ---------(3)
from (1) & (3)
x^2-16=3x^2-48
32=2x^2
x=4(2)^1/2
so perimeter=8+8(2)^1/2
- 10 years agoHelpfull: Yes(2) No(0)
- first,it may or may not be rectangle.
second,let us consider x to be 3 equally divided line segments.
so perimeter would be equal to 4*square root of (9x^2-y^2).
- 11 years agoHelpfull: Yes(1) No(4)
- 9 1's are there.dont confuse here
first multiply the numbers where ever multiplication symbol is present then go for repective binary format.then count number of 1's.u ll get it.
- 11 years agoHelpfull: Yes(0) No(1)
- nt gettng d soln..could sm1 explain please..
- 11 years agoHelpfull: Yes(0) No(1)
- 18 be the perimeter
- 11 years agoHelpfull: Yes(0) No(1)
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