Your Turn: In the diagram, AB = 12, DX = 2.5, and BX = 5. Find CD. Show all work.
Solution:
In ΔABX and ΔCDX,
∠CDX=∠ABX=90°
Also,∠CXD=∠AXB (as shown in figure)
∠DCX=∠BAX, as two angles of the triangle are equal. The third angle is also equal.
So ΔCDX≈ΔABX
Hence, the ratio of sides must be equal.

Now, using,



Now, To solve for CD, Let us multiply by 12 on both sides



CD=6 Answer