You can put this solution on YOUR website! One diagonal of a rhombus has the same length, 10cm, as each side. How long is the other diagonal
Then it it is two equilateral triangles with a common side, like this,
where all the black line segments are 10 cm each:
We want to know the length of the green line segment:
So we look at just one half of the top which is this:
The bottom side is 5cm because the diagonals of a parallelogram bisect
each other (and a rhombus is a parallelogram). The hypotenuse is a side
of the rhombus, so it is 10cm, so the green line in that triangle is
found by the Pythagorean theorem:
c² = a² + b²
10² = 5² + b²
100 = 25 + b²
75 = b²
= b
= b
5 = b
So the entire diagonal is twice that or
10 or about 17.32cm
Edwin
