Question

Diagonals of rhombus are 20 and 21 what is its perimeter

Answer 1

Diagonal 1 = 20

Diagonal 2 = 21

Lets find side of rhombus

First divide the rhombus in four triangles

Second take a triangle and use pythagoras theorem to find side

Let the side be X

So X square = Half of diagonal 1 square + Half of diagonal 2 square

 X square = 10 square + 10.5 square

X square = 100 + 110.25

X square = 210.25

X = root under 210.25

X = 14.5

So the perimeter of the rhombus will be 4* side

                                        = 4*14.5

                                        =58

I hope I helped you