Which law did Mendel propose based on his dihybrid cross experiment?

In a cross between yellow round $(YYRR)$ and pure breeding pea plants having green wrinkled $(yyrr)$ seeds,find out the total number of seeds (plants) having yellow colour in the $F_2$ generation out of $16$ offspring.

When a cross is made between a tall plant with yellow seeds $(TtYy)$ and a tall plant with green seeds $(Ttyy)$,what proportions of phenotypes in the offspring could be expected to be:
$(a)$ Tall and green.
$(b)$ Dwarf and green.

In the $F_2$ generation of a dihybrid cross of homozygous parents,the number of genotypes and phenotypes will be respectively . . . . . . .

Which law is demonstrated by Mendel's dihybrid cross?

Pure homozygous offsprings in a dihybrid cross in the $F_2$ generation will be