21. To find out how wide a river is, Jon and Sally mark an X at the spot directly across from a big rock on the other side of the river. Then they walk in a straight line along the river, perpendicular to the straight line between the X and the rock. After walking for 20 feet Jon stops while Sally continues along the straight line for another 10 feet. Then she makes a 90 degree turn and walks for 30 feet. When she stops and looks at the rock she sees that the straight line from her to the rock passes through Jon. What is the distance from X to the rock? distance X Rock 20 ft Jon 10 ft Тurn 30 f »» Sally а. 63 feet с. 50 feet b. 60 feet d. 30 feet

21. To find out how wide a river is, Jon and Sally mark an X at the spot directly across from a big rock on the other side of the river. Then they walk in a straight line along the river, perpendicular to the straight line between the X and the rock. After walking for 20 feet Jon stops while Sally continues along the straight line for another 10 feet. Then she makes a 90 degree turn and walks for 30 feet. When she stops and looks at the rock she sees that the straight line from her to the rock passes through Jon. What is the distance from X to the rock? distance X Rock 20 ft Jon 10 ft Тurn 30 f »» Sally а. 63 feet с. 50 feet b. 60 feet d. 30 feet

Elementary Geometry For College Students, 7e

7th Edition

ISBN:9781337614085

Author:Alexander, Daniel C.; Koeberlein, Geralyn M.

Publisher:Alexander, Daniel C.; Koeberlein, Geralyn M.

ChapterP: Preliminary Concepts

SectionP.CT: Test

Problem 1CT

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Question

21. To find out how wide a river is, Jon and Sally mark an X at the spot directly across from a big rock on the
other side of the river. Then they walk in a straight line along the river, perpendicular to the straight line
between the X and the rock. After walking for 20 feet Jon stops while Sally continues along the straight line
for another 10 feet. Then she makes a 90 degree turn and walks for 30 feet. When she stops and looks at the
rock she sees that the straight line from her to the rock passes through Jon. What is the distance from X to the
rock?
Rock
distance
20 ft
Jon
10 ft.
-2» Sally
Turn 30 ft
а.
63 feet
с.
50 feet
b.
60 feet
d.
30 feet

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