The missing lengths of the similar triangles are:
a) x = 3
y = 5
b) x = 2
y = 8/3
What is the ratio of the similar triangles?
Two triangles are similar if the ratio of their corresponding sides are equal.
We are told that the triangles are similar and as such:
a) x/9 = 4/12
x = (9 * 4)/12
x = 3
Similarly:
y/15 = 4/12
y = (15 * 4)/12
y = 5
b) 6/x = 9/3
Thus:
9x = 18
x = 2
8/y = 9/3
y = (3 * 8)/9
y = 8/3