Answer:
4 units!!
Explanation:
Both triangles as shown are IDENTICAL copies, which means they both have the same lengths and area.
The first triangle has an area of 8 squared units, because remember that the formula a triangle's area is (A = 1/2bh). This means that the other triangle has to have an area of 8 squared units. Therefore, the missing length (which is the base) of the second triangle has to be 4 units for the area to be 8 squared units. This missing length of the second triangle is the missing length of the first triangle.
Hence, the missing length is 4 units. If you have any concerns or questions, please let me know!!! Have a nice day!! :)