Let the shorter diagonal be x, then x^2 = 6^2 + 10^2 - 2 x 6 x 10 x cos 70 = 36 + 100 - 120 cos 70 = 136 - 41.04 = 94.96 x = sqrt(94.96) = 9.7 cm
The other angle of the parallelogram is 1/2(360 - 2(70)) = 1/2(360 - 140) = 1/2(220) = 110 Let the longer diagonal be y, then y^2 = 6^2 + 10^2 - 2 x 6 x 10 x cos 110 = 36 + 100 - 120 cos 110 = 136 + 41.04 = 177.04 y = sqrt(177.04) = 13.3 cm.
Therefore, the length of the diagonals are 9.7 cm and 13.3 cm.
This is because 25% of $260 is $65. Then you must subtract that from the original price. $260 - $65 = $195. Then, it says '10% off the sale price'. The sale price is $195. 10% of this is 19.5. Finally, you subtract this from the $195, with a final amount of $175.50