21.9k views
17 votes
Help! I would like a walkthrough of how to do this problem, as i cant figure out how to. Thanks!

Help! I would like a walkthrough of how to do this problem, as i cant figure out how-example-1
User Exabiche
by
5.0k points

1 Answer

13 votes

Answer:

  • a = 4.5
  • b = 7.5

Explanation:

You want the lengths of sides marked 'a' and 'b' in the given right triangle figure.

Similar triangles

All of the triangles in the figure are similar to each other. This gives rise to some proportional relations that are useful for solving this problem.

short side/long side = 6/8 = a/6

8a = 36 . . . . . . cross multiply

a = 36/8 = 4.5

long side/hypotenuse = 8/10 = 6/b

8b = 60 . . . . . . . cross multiply

b = 60/8 = 7.5

The lengths 'a' and 'b' are 4.5 and 7.5, respectively.

__

Additional comment

These are sometimes given as "geometric mean" relationships:

6 = √(8·a)

b = √(a·(a+8))

10 = √(8·(8+a))

where √(pq) is the geometric mean of p and q.

Another way to solve this is to recognize the given triangle is a 3-4-5 right triangle. The other similar triangles will have these same ratios:

3 : 4 : 5 = a : 6 : b ⇒ a = 3(6/4) = 4.5, b = 5(6/4) = 7.5

<95141404393>

User Abdiel
by
4.7k points