GeometryMrs. Blanco

Identify similar triangles

Use similar triangles in real-life problems

In the diagram, ∆BTW ~ ∆ETC

a) Write the statement of proportionality.

b) Find mTEC. mTEC = 79°

c) Find ET and BE NEXT SLIDE

12

203

T

B W

E C

79°

34°

ET TC ECBT TW BW

In the diagram, ∆BTW ~ ∆ETC.

c. Find ET and BE.

12

203

T

B W

E C

79°

34°

CEWB

ETBT

=

312

ET20

=

3(20) = 12ET

ET=5

Write proportion.

Substitute values.

Divide

So, ET is 5 units and BE is 15 units.

Cross Multiply

If two angles of one triangle are congruent to the two angles of another triangle, then the two triangles are similar.

If K Y and J X, then ∆JKL ~ ∆XYZ.

K

J

L

Y

X

Z

x=24 and y=16Yes, ΔPQR~ΔLMN

BX= 0.75 milesCX= 2.25 miles