Help me solve?? Triangle?

Question

2) Triangle RST is similar to triangle UVW. (a) What is the value of “x” to the nearest tenth? (b) What proportion may be used to solve for “x”?

http://s218.photobucket.com/albums/cc35/stephanielazar1992/?action=view&current=untitled-12.jpg

Triangle ABC is similar to triangle JKL. (a) What is the value of “x”? (b) What proportion may be used to solve for “x”?

http://s218.photobucket.com/albums/cc35/stephanielazar1992/?action=view&current=untitled-13.jpg

Answer 1

For the blue triangles, the following should both be true.

One proportion which could be used is:

x / 9 = 8 / 16

This gives:

x = 9 * 8 / 16

= 4.5 exactly.

Another proportion is:

x / 10 = 8 / 18

This gives:

x = 10 * 8 / 18

= 4.4 to the nearest tenth.

I suggest that the side labelled 8 should be 8.1.

Then the second calculation would be:

x / 10 = 8.1 / 18

x = 10 * 8.1 / 18

= 4.5 exactly,

agreeing with the first one.

For the yellow triangles, one proportion is:

x / 14.8 = 11.1 / 3.7

This gives:

x = 14.8 * 11.1 / 3.7

= 44.4 exactly.

Another is:

x / 29.6 = 11.1 / 7.4

This gives:

x = 29.6 * 11.1 / 7.4

= 44.4 exactly.

The results agree, and so the blue triangles really are similar.