A 40-foot television antenna stands on top of a building. From a point on the ground, the angles of elevation of the top and bottom of the antenna, respectively, have measurements of 56 degrees and 42 degrees. How tall is the building?

1 Answer
Oct 24, 2015

The building is (approximately) #62# feet tall.

Explanation:

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#b/d = tan(42^@) = 0.900404#
#color(white)("XXX")rarr d = b/0.900404#

#(40+b)/d = tan(56^@) = 1.482561#
#color(white)("XXX")rarr 40+b = (b/0.900404)xx1.482561#

#color(white)("XXX")rarr b+40=1.646550766xxb#

#color(white)("XXX")rarr 0.64655076xxb = 40#

#color(white)("XXX")rarr b = 40/0.64655076 = 61.86675838#