Since we're given the 45 deg angle, we know that each side of the quadrilateral makes a 45-45-90 triangle.
We also know that the hypotenuse of the 45-45-90 is 5*sqrt(2)
The proportions for a 45-45-90 are 1-1-sqrt(2), so the height of the quadrilateral is 5.
Finally, multiply the base with the height = [5*sqrt(2)] * [5] = 25*sqrt(2)
Hope that helps.
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Source: Beat The GMAT — Problem Solving |
Hi sadwoski
Can i assume this Quadrilateral to be a Rhombus ?
I couldn't get your 1st statement that each side of quad make 45 - 45 -90
Can i assume this Quadrilateral to be a Rhombus ?
I couldn't get your 1st statement that each side of quad make 45 - 45 -90
Good one Sadowski.
Just to elaborate, the area of a rhombus (yes, quadrilateral with
4 equal sides) is =
1/2* product of length of diagonals
(or)
product of side * perpendicular distance between two sides (height)
In this case, if we drop a line from B perpendicular to AD, we will
get a 45-45-90 triangle with 5*sqrt-2 as the hypotenuse.
So, we know height = 5.
Area hence follows as side * height = 5*sqrt-2 * 5 = 25 * sqrt-2
For more details, visit your friendly wikipedia link --
https://en.wikipedia.org/wiki/Rhombus#Area
Just to elaborate, the area of a rhombus (yes, quadrilateral with
4 equal sides) is =
1/2* product of length of diagonals
(or)
product of side * perpendicular distance between two sides (height)
In this case, if we drop a line from B perpendicular to AD, we will
get a 45-45-90 triangle with 5*sqrt-2 as the hypotenuse.
So, we know height = 5.
Area hence follows as side * height = 5*sqrt-2 * 5 = 25 * sqrt-2
For more details, visit your friendly wikipedia link --
https://en.wikipedia.org/wiki/Rhombus#Area
Area of a parallelogram = Base * height
Angle BAD = 45
Drop a perpendicular from vertex B on AD
Now the triangle becomes a 45-45-90 triangle with sides in the ratio 1:1:sqr rt.2
Hypotenuese of the Triangle = BA = 5* sqr rt. 2...Hence height = 5
Hence Area of the figure = 5 * sqr rt. 2 * 5 = 25 sqr rt. 2
Angle BAD = 45
Drop a perpendicular from vertex B on AD
Now the triangle becomes a 45-45-90 triangle with sides in the ratio 1:1:sqr rt.2
Hypotenuese of the Triangle = BA = 5* sqr rt. 2...Hence height = 5
Hence Area of the figure = 5 * sqr rt. 2 * 5 = 25 sqr rt. 2
















