Answer:
x=5cm
Step-by-step explanation:
according to the picture , those two triangles are similar triangles,
so their three sides should be proportional
then :
32/4=40/x
8=40/x
x=5
As two angles are equal pf the two triangles , they are similar
Thus
40/x = 32/4
40/x = 8
x = 5
