Question

How to find the angle marked

Answer 1

#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.