#6). The tangent of an angle in a right triangle is
(opposite side) / (adjacent side) .
The side opposite the marked angle is 4cm.
The side adjacent to the marked angle is 12cm.
The tangent of the marked angle is (4cm / 12cm) = 1/3 .
The marked angle is the angle whose tangent is 1/3 .
You can find that online, or with your calculator, slide rule, Curta, or book.
#7). The cosine of an angle in a right triangle is
(adjacent side) / (hypotenuse) .
The side adjacent to the marked angle is 15m.
The hypotenuse is 19m.
The cosine of the marked angle is (15m / 19m) = about 0.78947...
The marked angle is the angle whose cosine is 0.78947... .
You can find that online, or with your calculator, slide rule, Curta, or book.
