Question

A parallelogram has side lengths of 40 and 75 units. One diagonal has a length of 70 units. Approximately how long is the other diagonal?

Answer 1

98 units

Explanation:

Diagonal=√side1²+side2²−2⋅side1⋅side2⋅cos(corresponding angle - a)

70² = 40²+75²-2*40*75⋅cos(a)

cos(a) = (40²+75²-70²) / 2*40*75

cos(180°-a) = -cos(a)

Other diagonal² = 40²+75²-2*40*75* (-(40²+75²-70²) / 2*40*75)

Other diagonal = 97.72