8.3. Inscribed Similar Triangles http://www.ck12.org
Watch this video for help with the Examples above.
MEDIA
Click image to the left for more content.CK-12 Foundation: Chapter8InscribedSimilarTrianglesB
Concept Problem Revisited
The average rate of increase can be found by using the geometric mean.
x=√
0. 213 · 0. 16 = 0. 1846
Over the two year period, housing prices increased 18.46%.
Vocabulary
If two objects aresimilar, they are the same shape but not necessarily the same size. The corresponding angles
of similar polygons are congruent and their sides are proportional in length. Thegeometric meanof two positive
numbersaandbis the numberx, such thatxa=bxorx^2 =abandx=
√
ab.Guided Practice
- Find the value ofx.
- Find the value ofyin 4 RSTabove.
- Find the geometric mean of 18 and 54.
- Find the value ofxandy.
Answers:
- Let’s set up a proportion.
shorter leg in 4 SV T
shorter leg in 4 RST=
hypotenuse in 4 SV T
hypotenuse in 4 RST
4
x=
x
20
x^2 = 80
x=√
80 = 4
√
5
- Use the Pythagorean Theorem.