Answer:
side x is 5 cm long
Explanation:
Use proportions, given that the two triangles are similar because they contain three equal angles:
One angle due to connected by the vertex (oppose by the vertex), another angle as marked with the tick, and the third one has to be the same due to the fact that the addition of the three internal angles of a triangle must equal 180 degrees.
Then our proportion becomes:
![(4)/(32) =(x)/(40)](https://img.qammunity.org/2021/formulas/mathematics/college/mb1f7rsr0sst20lymjl3ip0d42c9z6gt9g.png)
And then we solve for x by multiplying both sides by 40 (to eliminate the denominator on the right):
![(4)/(32) =(x)/(40) \\(4*40)/(32) =x\\ x=5\,\,cm](https://img.qammunity.org/2021/formulas/mathematics/college/tbhav22b9h8c34dtslk038spxh6pw0iofl.png)