Answer:
see explanation
Step-by-step explanation:
Using the tangent ratio in the right triangle
tan A =
=
=
, then
∠ A =
(
) ≈ 41° ( to the nearest degree )
The sum of the angles in the triangle = 180° , then
∠ B + 41° + 90° = 180°
∠ B + 131° = 180° ( subtract 131° from both sides )
∠ B = 49°
Using Pythagoras' identity in the right triangle
AB² = BC² + AC² = 7² + 8² = 49 + 64 = 113 ( take square root of both sides )
AB =
≈ 10.6 ( to the nearest tenth )
So 2x+12=5x-9
you want all of the unknowns on one side and all of the known values on the other or
subtract 2x from both sides
12=3x-9
add 9 to both sides
21=3x
divide both sides by 3
7=x
Answer:
x=26°
Step-by-step explanation:
3x-14+x+90=180
4x-14=90
4x=104
x=104/4
x=26°
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