Rhombus proof

Given: ABCD is a parallelogram,
Prove: ABCD is a rhombus

Ithink the answer is discovery verbs because they are quite similar to the verb 'discovering'

Do the inverse operation

Hello! i hope this
since the cosine is the ratio of the adjacent side to the hypotenuse, you can see that cos 60° = ½. answer. according to the property of cofunctions (topic 3), sin 30° is equal to cos 60°. sin 30° = ½.