In the figure above, triangle ABC is similar to triangle ADE. If side AC = 8 cm, side CE = 4 cm and side BC = 5 cm, then what is the measure of side DE?
Since triangle ABC is similar to triangle ADE, the corresponding sides are proportional.
Let x be the measure of side DE.
Therefore, we have:
AC/AD = BC/DE
8/x = 5/4
Cross multiplying, we get:
4*8 = 5*x
32 = 5x
x = 32/5
x = 6.4 cm
Therefore, the measure of side DE is 6.4 cm.