436,415 views
20 votes
20 votes
Reading list

All changes saved
8. The two diagonals of a parallelogram meet at a 60° angle. The diagonals are 10 cm and 6 cm long. Find the lengths of the sides of the parallelogram.
Target due: 1/14/22 52% 5
10 cm
0 14 cm, 8.7 cm
4.4 cm, 2.8 cm
CLASS INFO
O 4.4 cm, 4.4 cm
7 cm, 4.4 cm
818-572-
ak:
tnp-
2 01:15:20

User LZW
by
2.8k points

1 Answer

13 votes
13 votes

9514 1404 393

Answer:

7 cm, 4.4 cm

Explanation:

The side lengths can be found from the law of cosines. Each triangle has legs 3 cm and 5 cm. The angle between these will be 60° or 120°. Then the two sides of the parallelogram are ...

s = √(a² +b² -2ab·cos(C))

s = √(3² +5² -2·3·5·(±1/2)) = √(34 ±15) = {√49, √19}

The two side lengths are 7 cm and about 4.4 cm.

Reading list All changes saved 8. The two diagonals of a parallelogram meet at a 60° angle-example-1
User Eugene Trofimenko
by
3.0k points