There are ten kids in a class. When any two meet, they shake their hands. Before the class starts, how many handshakes are there?

45

Step-by-step explanation:

Ok, Kid 1 can meet other 9 kids, so we have 9 handshaks.

Kid 2 can also meet other 9 kids, but he already meet kid 1, so we are not counting that handshake, this means that now we have 8 handshakes.

Kid 3 can also meet 9 kids, but we already counted the handshake with kid 1 and kid 2, so here we have other 7 andshakes.

And so on, so we have a total of:

9 + 8 + 7 + 6 + 5 + 4 +3 + 2 + 1 = 45 handshakes in total.

answer: ouch. thats difficult

step-by-step explanation:

∠lno ≅ ∠lnm

∠oln ≅ ∠mln

step-by-step explanation:

given   that triangle lno is congruent to triangle lnm.

we have to fill up the blanks in the given question.

according to above order of congruency   kept in mind we can say that

∠lno ≅ ∠lnm

∠oln ≅ ∠mln

ln ≅ ln due to common in both.

hence, by sas congruency,

the side angle side rule   states that if two sides and the included angle of one triangle are congruent to another triangle, then these two triangles are congruent.