How do you use special right triangles to solve for missing sides? (30-60-90 and 45-45-90 triangles)
1 answer:
Answer: see below
Step-by-step explanation:
30 - 60 - 90 triangles have angles in the triangle measuring 30, 60, and 90 degrees. A 30 - 60 - 90 triangle also has special side ratios according to a side's location in the triangle.
The side across from the 30 degree angle is represented by x.
The side across from the 60 degree angle is represented by x.
The side across from the 90 degree angle is represented by 2x.
45 - 45 - 90 triangles have angles in the triangle measuring 45, 45, and 90 degrees. A 45 - 45 - 90 triangle has special side ratios similar to the 30 - 60 - 90 triangle.
The side across from either of the 45 degree angles is represented by x.
The side across from the 90 degree angle is represented by x.
These ratios can be used to find missing sides. If you know that a triangle is one of these special triangles and you also know one of its side lengths, you can plug the known length in for x in the proper place.
EX: you have a 30 - 60 - 90 triangle with a side length of 2 across from the 30 degree angle. You then know that the side across from 60 is 2 and the side across from 90 is 4.
You might be interested in
To solve this problem, we must imagine the triangles and parallel lines which are formed. It is best to draw the triangle described in the problem so that you can clearly understand what I will be talking about.
The first step we have to do is to make an equality equation in triangle ABC.
In triangle ABC, we are given that lines XY and BC are two parallel lines (XY || BC). Therefore this means that:
AX / XB = AY / YC ---> 1
The next step is to make an equality equation in triangle AXC.
We are given that lines ZY and XC are two parallel lines (ZY || XC). Therefore this also means that:
AZ / ZX = AY / YC ---> 2
Combining 1 and 2 since they have both AY / YC in common:
AX / XB = AZ / ZX
we are given that:
AZ = 8, ZX = 4 therefore AX = AZ + ZX = 12, hence
12 / XB = 8 / 4
XB = 6
