HEYA!!!♥♥♥ WELCOME TO THIS WEEK'S MIRACLE QUESTION
IF A TRIANGLE AND PARALLELOGRAM LIE ON SAME BASE AND BETWEEN
SAME PARALLELS, THENNPROVE THAT AREA OF TRIANGLE IS EQUAL TO 1/2
AREA OF PARALLELOGRAM.
ONLY BRAINLY AND MYSTERY ANSWERES BE MARKED BRAINLIEST.
Attachments:
man5446:
it was very easy question
Answers
Answered by
155
In the figure, we have a ∆ACP and a ||gm ABCD. We have to prove that area of ∆ = 1/2 area of ||gm if they lie on same base and between the same parallel.
Method 1 :-
Drop the height of parallelogram from the point D or C. Let the height be denoted by h
So area of ||gm would be base × height
= AB × h
Now since they lie between the same parallel, the height of the traingle would be equal to the height of ||gm
So area of triangle = 1/2 × base × Height
= 1/2 × AB × h
= 1/2 × area of ||gm ABCD
Hence proved
Method 2
(Lengthy but effective)
Construct a line parallel to AP. Let the line intersect CD at Q
Now we have AB || CD (since ABCD is a ||gm)
Hence, AB || PQ (Since CD coincides with PQ)
And, BQ || AP (By construction)
So ABPQ is a ||gm (if opposite sides are parallel, then the figure is a ||gm)
And ABCD is also a ||gm.
Since both parallelogram lie between same parallel (AB || PC) and on same base (AB),
area of ABPQ = area of ABCD
Now, for ABQP, PB is the diagonal.
In ∆PAB and ∆PBQ,
PA = BQ (opposite sides of ||gm are equal)
PQ = AB(opposite sides of a ||gm are equal)
PB = PB (common)
Hence, ∆PAB is congruent to ∆PBQ (SSS)
So area of PAB = area of PBQ
(congruent figures have equal area)
And area PAB + area PBQ = area ABPQ
=> area PAB + area PAB = area ABPQ
(since, area PAB = area PBQ)
=> 2 ar(PAB) = ar(ABPQ)
=> ar(PAB) = 1/2 × ar(ABPQ)
Now ar(ABPQ) = ar(ABCD)
=> ar(PAB) = 1/2 × ar(ABCD)
Hence, if a triangle and a ||gm lie on same base and between the same parallel, then the area of triangle = 1/2 of area of parallelogram.
Method 1 :-
Drop the height of parallelogram from the point D or C. Let the height be denoted by h
So area of ||gm would be base × height
= AB × h
Now since they lie between the same parallel, the height of the traingle would be equal to the height of ||gm
So area of triangle = 1/2 × base × Height
= 1/2 × AB × h
= 1/2 × area of ||gm ABCD
Hence proved
Method 2
(Lengthy but effective)
Construct a line parallel to AP. Let the line intersect CD at Q
Now we have AB || CD (since ABCD is a ||gm)
Hence, AB || PQ (Since CD coincides with PQ)
And, BQ || AP (By construction)
So ABPQ is a ||gm (if opposite sides are parallel, then the figure is a ||gm)
And ABCD is also a ||gm.
Since both parallelogram lie between same parallel (AB || PC) and on same base (AB),
area of ABPQ = area of ABCD
Now, for ABQP, PB is the diagonal.
In ∆PAB and ∆PBQ,
PA = BQ (opposite sides of ||gm are equal)
PQ = AB(opposite sides of a ||gm are equal)
PB = PB (common)
Hence, ∆PAB is congruent to ∆PBQ (SSS)
So area of PAB = area of PBQ
(congruent figures have equal area)
And area PAB + area PBQ = area ABPQ
=> area PAB + area PAB = area ABPQ
(since, area PAB = area PBQ)
=> 2 ar(PAB) = ar(ABPQ)
=> ar(PAB) = 1/2 × ar(ABPQ)
Now ar(ABPQ) = ar(ABCD)
=> ar(PAB) = 1/2 × ar(ABCD)
Hence, if a triangle and a ||gm lie on same base and between the same parallel, then the area of triangle = 1/2 of area of parallelogram.
Answered by
127
correct answer of the question....
mark me as brainliest if u like plzzz..
and thanks for asking this question...
im practicing 9th syllabus so it helped me a lot...XD
mark me as brainliest if u like plzzz..
and thanks for asking this question...
im practicing 9th syllabus so it helped me a lot...XD
Attachments:
Similar questions