Answer all the questions below and press submit to see how many you got right.
Cos : The cosine of an angle $0\leq\alpha\leq 180^{\circ}$ or $\cos \alpha$ is defined by finding a right triangle with angle $\alpha$ and dividing the length of the leg adjacent to $\alpha$ by the length of the hypotenuse. For arbitrary angles the cosine function can be extended in a periodic way by inscribing the right triangle in a circle. The cosine can be used to calculate unknown side lengths in a triangle via the cosine law and in the case of right triangles via its definition. The Pythagorean theorem implies that $\cos^2 \alpha+\sin^2 \alpha=1.$
Sin : The sine of an angle $0\leq\alpha\leq 180^{\circ}$ or $\sin \alpha$ is defined by finding a right triangle with angle $\alpha$ and dividing the length of the leg opposite to $\alpha$ by the length of the hypotenuse. For arbitrary angles the sine function can be extended in a periodic way by inscribing the right triangle in a circle. The sine can be used to calculate unknown side lengths in a triangle via the sine law and in the case of right triangles via its definition. The Pythagorean theorem implies that $\cos^2 \alpha+\sin^2 \alpha=1.$
Tan : The tangent of an angle $0\leq\alpha\leq 180^{\circ}$ or $\tan \alpha$ is defined by finding a right triangle with angle $\alpha$ and dividing the length of the leg opposite to $\alpha$ by the length of the leg adjacent to $\alpha.$ For arbitrary angles the tangent function can be extended in a periodic way by inscribing the right triangle in a circle. The tangent function can be used to calculate unknown side lengths and angles in right triangles via its definition. We have $\tan \alpha=\frac{\sin \alpha}{\cos \alpha}.$
$\tan 0^{\circ}=?$
Adjacent : Adjacent means next to each other.
Angle : If two line segments (or rays) both start at a common point the opening between the two line segments is called an angle. The common point is called vertex of the angle. The size of an angle is measured in degrees.
Cot : In a right triangle with one of the angles adjacent to the hypotenuse being equal to $\alpha,$ $\cot \alpha$ is defined as the length of the leg adjacent to the angle divided by the length of the other leg. We have $\cot \alpha= \frac{1}{\tan \alpha} =\frac{\cos \alpha}{\sin \alpha}.$
Leg of a right triangle : A leg of a right triangle is one of the two sides in a right triangle that form the right angle.
Length : Length is the attribute of a one-dimensional shape that can be measured with a measuring tape.
Ratio : A ratio is a comparison of two numbers using a division.
Right angle : A right angle is an angle equal to $90^{\circ}.$
Right triangle : A right triangle is a triangle that has a right angle. The sides that form the right angle are called legs, the third side is called hypotenuse. The area of a right triangle is half the product of the lengths of the two legs. The Pythagorean theorem is an important theorem for right triangles that allows to calculate the third side of a right triangle given the other two.
Trigonometric function : Trigonometric functions are the functions commonly used in trigonometry like $\sin x,$ $\cos x,$ $\tan x,$ $\cot x$ and their inverse functions $\arcsin x,$ $\arccos x,$ and $\arctan x.$
Given is a right triangle. One of the other angles is $\alpha$, the leg adjacent to this angle has length $b$, and the leg opposite to this angle has length $a.$ Then $\frac{a}{b}=?$
Addition : Addition is the mathematical operation that describes increasing a number by an amount equal to a second number. The mathematical symbol for addition is the plus sign $+.$ The term addition is also used for a generalization of this basic operation on numbers to functions, vectors and matrices.
Hypotenuse : The hypotenuse in a right triangle is the side of the right triangle that does not have any endpoints at the corner with the right angle. The hypotenuse is the longest side in a right triangle and its length can be calculated from the other two side lengths using the Pythagorean theorem.
Pi : Pi or $\pi$ is an irrational number approximately equal to 3.14 that is defined as the quotient of the circumference and the diameter of a circle.
Triangle : A triangle is a polygon with three corners and three sides. You can calculate the area of a triangle by multiplying half the length of the base by the height on that base. The sum of the interior angles in a triangle is always $180^{\circ}.$
$\sin 90^{\circ}=\sin \frac{\pi}{4}=?$