91Ó°ÊÓ

\(\cos 90^{\circ}\)

Given a square with side length \(x\), draw the two diagonals. The result is 4 special triangles. Describe these triangles. What are the angle measures?

\(\sin 90^{\circ}\)

If the longer leg of a \(30^{\circ}-60^{\circ}-90^{\circ}\) triangle has length \(134.75\) centimeter, what are the lengths of the other leg and the hypotenuse? Round answers to two decimal places.

If the measurement 700 feet has been rounded to the nearest whole number, it has three significant digits.

Find the exact value of \(\cos 75^{\circ}-\left(\csc 45^{\circ}\right)\left(\cos 30^{\circ}\right)\), given that \(\sin 15^{\circ}=\frac{\sqrt{6}-\sqrt{2}}{4}\).

From the top of a 12-foot ladder, the angle of depression to the far side of a sidewalk is \(45^{\circ}\), while the angle of depression to the near side of the sidewalk is \(65^{\circ}\). How wide is the sidewalk?

Calculate \(\csc 40^{\circ}\) the following two ways: a. Find \(\sin 40^{\circ}\) (round to three decimal places), and then divide 1 by that number. Write this last result to five decimal places. b. First find \(\sin 40^{\circ}\) and then find its reciprocal. Round the result to five decimal places.

Use a calculator to find \(\sin ^{-1}\left(\sin 40^{\circ}\right)\).

Use a calculator to find \(\cos ^{-1}\left(\cos 17^{\circ}\right)\).