Steve has 11 biscuits in a tin. There are 4 digestive, 2 chocolate and 5 ginger biscuits.

Steve takes two biscuits at random from the tin.

Work out the probability that he chooses two different types of biscuits.

Given: ae ≅ ce ; de ≅ be prove: abcd is a parallelogram. we have that ab || dc. by a similar argument used to prove that △aeb ≅ △ced, we can show that △ ≅ △ceb by. so, ∠cad ≅ ∠ by cpctc. therefore, ad || bc by the converse of the theorem. since both pair of opposite sides are parallel, quadrilateral abcd is a parallelogram.