Area of a quadrilateral or parallelogram as half the cross product of its diagonals
This type of question, asked 6 times: 1 Feb 2023, 8 Apr 2023, 30 Jan 2024, 5 Apr 2024, 6 Apr 2024, 9 Apr 2024. All 6 questions below, oldest first.
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Question 1
1 Feb 2023
90
A(2,6,2),B(−4,0,λ),C(2,3,−1) and D(4,5,0),∣λ∣≤5 are the vertices of a quadrilateral ABCD. If its area is 18 square units, then 5−6λ is equal to
Question 2
8 Apr 2023
161
The area of the quadrilateral ABCD with vertices A(2,1,1),B(1,2,5),C(−2,−3,5) and D(1,−6,− 7) is equal to
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Question 3
30 Jan 2024
78
Let A(2,3,5) and C(−3,4,−2) be opposite vertices of a parallelogram ABCD if the diagonal BD=i+2j+3k then the area of the parallelogram is equal to
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Question 4
5 Apr 2024
78
If A(1,−1,2),B(5,7,−6),C(3,4,−10) and D(−1,−4,−2) are the vertices of a quadrilateral ABCD, then its area is :
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Question 5
6 Apr 2024
62
If A(3,1,−1),B(35,37,31),C(2,2,1) and D(310,32,3−1) are the vertices of a quadrilateral ABCD, then its area is
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Question 6
9 Apr 2024
170
Let a=2i+αj+k,b=−i+k,c=βj−k, where α and β are integers and αβ=−6. Let the values of the ordered pair (α,β) for which the area of the parallelogram of diagonals a+b and b+c is 221, be (α1,β1) and (α2,β2). Then α12+β12−α2β2 is equal to