Page 128 - Math Course 3 (Book 2)

Similarity of Triangles

Your Turn! Indirect Measurement
INDIRECT MEASUREMENT
Are Triangles Similar? On her trip along the East coast, Jennie stops to
look at the tallest lighthouse in the U.S. located at
In the figure, OW = 7, BW = 9, WT = 17.5, and Cape Hatteras, North Carolina. At that particular
WI = 22.5. Determine which triangles in the time of day, Jennie measures her shadow to be 1
figure are similar. feet 6 inches in length and the length of the
shadow of the lighthouse to be 53 feet 6 inches.
A. ΔOBW ~ ΔITW B O Jennie knows that her height is 5 feet 6 inches.
B. ΔOBW ~ ΔWIT What is the height of the Cape Hatteras
C. ΔBOW ~ ΔTIW lighthouse to the nearest foot?
D. ΔBOW ~ ΔITW w

Answer

T I
x ft

5 ft 6 in.

Parts of Similar Triangles 1 ft 6 in.
53 ft 6 in.
ALGEBRA Given AB || DE, AB = 38.5, DE = 11,
AC = 3x + 8, and CE = x + 2, find AC.
A. 196 ft B. 39 ft
C. 441 ft D. 89 ft
A. 2 A 38.5 B
B. 4 Answer
C. 12
D. 14
3x + 8
Answer C

x + 2

D 11 E

ALGEBRA Given AB || DE, AB = 38.5, DE = 11,
AC = 3x + 8, and CE = x + 2, find CE.

A. 2
B. 4
C. 12
D. 14

Answer

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