Lin knows that angle A is congruent to angle D. She claims that triangles ABC and DEF must be similar. Convince Lin that the triangles are not similar.

In order to determine similarity between two triangles, you need at least 2 angles to be congruent. If only 1 angle is congruent, the triangles are not similar. This is true because if 2 of the angles are congruent, then the remaining angle must be congruent also.

E.g. ∠A and ∠D both equal 90°, but ∠B and ∠C = 45°. While, ∠E = 30° and ∠F = 60°.  

he spend 5.1 minutes chatting with his friends

step-by-step explanation:

2/5+1/2=9/10

6/1-9/10=5 1/10

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,