Kimoya W. x= y= More 1 Expert Answer
Mahmut S. answered • 07/30/21 SAT Math Expert Hello Kimoya. According to similarity rules; there is a ratio between height of triangles; 12/4 = 3. that means corresponding sides of left triangle multiplied by 3 to get the sides of troangle on the right. So 18/3 gives us x which is 6; 8*3 = y = 24 hope that helps Still looking for help? Get the right answer, fast.ORFind an Online Tutor Now Choose an expert and meet online. No packages or subscriptions, pay only for the time you need. Two triangles are Similar if the only difference is size (and possibly the need to turn or flip one around). These triangles are all similar: (Equal angles have been marked with the same number of arcs) Some of them have different sizes and some of them have been turned or flipped. For similar triangles:
and
Also notice that the corresponding sides face the corresponding angles. For example the sides that face the angles with two arcs are corresponding. Corresponding SidesIn similar triangles, corresponding sides are always in the same ratio. For example: Triangles R and S are similar. The equal angles are marked with the same numbers of arcs. What are the corresponding lengths?
Calculating the Lengths of Corresponding SidesWe can sometimes calculate lengths we don't know yet.
Example: Find lengths a and b of Triangle SStep 1: Find the ratioWe know all the sides in Triangle R, and The 6.4 faces the angle marked with two arcs as does the side of length 8 in triangle R. So we can match 6.4 with 8, and so the ratio of sides in triangle S to triangle R is: 6.4 to 8 Now we know that the lengths of sides in triangle S are all 6.4/8 times the lengths of sides in triangle R. Step 2: Use the ratioa faces the angle with one arc as does the side of length 7 in triangle R. a = (6.4/8) × 7 = 5.6 b faces the angle with three arcs as does the side of length 6 in triangle R. b = (6.4/8) × 6 = 4.8 Done! Two triangles are similar if they have:
But we don't need to know all three sides and all three angles ...two or three out of the six is usually enough. There are three ways to find if two triangles are similar: AA, SAS and SSS: AAAA stands for "angle, angle" and means that the triangles have two of their angles equal. If two triangles have two of their angles equal, the triangles are similar. Example: these two triangles are similar:If two of their angles are equal, then the third angle must also be equal, because angles of a triangle always add to make 180°. In this case the missing angle is 180° − (72° + 35°) = 73° So AA could also be called AAA (because when two angles are equal, all three angles must be equal). SASSAS stands for "side, angle, side" and means that we have two triangles where:
If two triangles have two pairs of sides in the same ratio and the included angles are also equal, then the triangles are similar. Example:In this example we can see that:
So there is enough information to tell us that the two triangles are similar. Using TrigonometryWe could also use Trigonometry to calculate the other two sides using the Law of Cosines: Example ContinuedIn Triangle ABC:
In Triangle XYZ:
Now let us check the ratio of those two sides: a : x = 22.426... : 14.950... = 3 : 2 the same ratio as before! Note: we can also use the Law of Sines to show that the other two angles are equal. SSSSSS stands for "side, side, side" and means that we have two triangles with all three pairs of corresponding sides in the same ratio. If two triangles have three pairs of sides in the same ratio, then the triangles are similar. Example:In this example, the ratios of sides are:
These ratios are all equal, so the two triangles are similar. Using TrigonometryUsing Trigonometry we can show that the two triangles have equal angles by using the Law of Cosines in each triangle: In Triangle ABC:
In Triangle XYZ:
So angles A and X are equal! Similarly we can show that angles B and Y are equal, and angles C and Z are equal. How do you find the length of a triangle with similar triangles?Calculating the Lengths of Corresponding Sides. Step 1: Find the ratio. We know all the sides in Triangle R, and. We know the side 6.4 in Triangle S. ... . Step 2: Use the ratio. a faces the angle with one arc as does the side of length 7 in triangle R. a = (6.4/8) × 7 = 5.6.. |