A parallelogram has sides of lengths 7 and 5, and one angle is 35°. Find the lengths of the diagonals. (Round your answers to two decimal places. Enter your answers as a comma-separated list.)
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Drawing might help.
Use the law of cosine:
c^2 = a^2 + b^2 - 2ab cos(C)
To find short diagonal,
c^2 = 7^2 + 5^2 - 2(7)(5) cos(35)
c = about 4.08
To find the long diagonal, (180 - 35 = 145)
c^2 = 7^2 + 5^2 - 2(7)(5) cos(145)
c = about 131.34
Use the law of cosine:
c^2 = a^2 + b^2 - 2ab cos(C)
To find short diagonal,
c^2 = 7^2 + 5^2 - 2(7)(5) cos(35)
c = about 4.08
To find the long diagonal, (180 - 35 = 145)
c^2 = 7^2 + 5^2 - 2(7)(5) cos(145)
c = about 131.34