In triangle ABC, how do you solve the right triangle given 'a' is 7 m, and the angle 'A' is 22 degrees?

1 Answer
Sep 29, 2015

(Assuming the right angle is at C)
#/_B = 68^@#
#c= 7/sin(22^@) meters#
#b=7/tan(22^@) meters#

Explanation:

Everything that follows is under the assumption that the right angle is #/_C#. If the intent is that #/_B# is the right angle, exchange #B# and #C# in the explanation below:

Since #/_A =22^@# and #/_C = 90^@#
and the sum of interior angles of a triangle is #180^@#
#rarr /_B = 68^@#

For the #/_A#
the opposite side is #a (=7)#m
the adjacent side is #b# and
the hypotenuse is #c#

#sin(22^@) = ("opposite")/("hypotenuse")= 7/c#

#rarr c= 7/sin(22^@)#

and

#tan(22^@) = ("opposite")/("adjacent") = 7/b#

#rarr b=7/tan(22^@)#

Note:
a calculator could be used to evaluate:
#color(white)("XXX")b=7/tan(22^@) ~=17.33#
and
#color(white)("XXX")c=7/sin(22^@) ~=18.69#