ABCD is a kite with $\angle A=46°$ and $\angle C=28°$. Find the measure of $\angle B$.

143°

ABCD is a kite . So, AB = BC and AD = DC

And diagonal AC and BD bisect their respective angles.

∠A = 46º and ∠C = 28º 

Diagonal AC bisect angle ∠A and ∠C

So, ∠BAC = 23º  and ∠ACB = 14º

In triangle ABC ,

∠BAC + ∠ACB + ∠ABC = 180º

23º + 14º + ∠ABC = 180º

∠ABC = 180º - 37º

= 143º