Right triangles & trigonometry Flashcards
What is the Pythagorean theorem?
In a right triangle, the square of the length of the hypotenuse is equal to the sum of the squares of the lengths of the other two sides.
True or False: The hypotenuse is the longest side of a right triangle.
True
Fill in the blank: In a right triangle, the two legs are the sides that form the ______.
right angle
What is the formula for calculating the area of a right triangle?
Area = 1/2 * base * height
Which trigonometric function is defined as the ratio of the opposite side to the hypotenuse?
Sine
What is the sine of a 30-degree angle?
0.5
If the opposite side is 3 and the hypotenuse is 5, what is the sine of the angle?
0.6
True or False: Cosine is the ratio of the adjacent side to the hypotenuse.
True
What is the cosine of a 60-degree angle?
0.5
Fill in the blank: The tangent function is the ratio of the ______ side to the adjacent side.
opposite
What is the tangent of a 45-degree angle?
1
If the adjacent side is 4 and the opposite side is 3, what is the tangent of the angle?
0.75
What is the relationship between the angles in a right triangle?
The sum of the two acute angles is 90 degrees.
True or False: In a right triangle, the two legs can be of equal length.
True
What is the length of the hypotenuse in a right triangle with legs of length 3 and 4?
5
Fill in the blank: The sides of a 30-60-90 triangle are in the ratio of ______.
1 : √3 : 2
What is the inverse function of sine called?
Arcsine
What is the inverse function of cosine called?
Arccosine
What is the inverse function of tangent called?
Arctangent
If the angle is 30 degrees, what is the cosine value?
√3/2
True or False: The angles in a right triangle can be more than 90 degrees.
False
What is the length of one leg of a right triangle if the hypotenuse is 10 and the other leg is 6?
8
Fill in the blank: The Law of Cosines is used to find a side of a triangle when you know two sides and the ______.
included angle
What is the angle in a right triangle if the opposite side is 1 and the adjacent side is √3?
30 degrees
True or False: The side opposite the largest angle in a triangle is always the longest side.
True
What is the tangent of a 30-degree angle?
√3/3
Fill in the blank: The ratio of the lengths of the sides of a triangle is known as its ______.
proportions
If a right triangle has an angle of 45 degrees, what are the lengths of the legs?
Equal lengths
What is the area of a right triangle with a base of 5 and a height of 12?
30
Fill in the blank: The hypotenuse of a right triangle is always opposite the ______.
right angle
What is the sine of a 90-degree angle?
1
True or False: The sides of a triangle can never be 0.
True
What is the cosine of a 30-degree angle?
√3/2
In a right triangle, if one angle measures 25 degrees, what is the other acute angle?
65 degrees
Fill in the blank: The longest side of a right triangle is called the ______.
hypotenuse
If the hypotenuse is 13 and one leg is 5, what is the other leg?
12
What is the tangent of a 60-degree angle?
√3
True or False: In a right triangle, the lengths of the legs must be positive numbers.
True
What is the formula for the Pythagorean theorem?
a² + b² = c²
Fill in the blank: The angles in a triangle add up to ______ degrees.
180
What is the sine of a 45-degree angle?
√2/2
What is the cosine of a 45-degree angle?
√2/2
If a right triangle has legs of lengths 7 and 24, what is the length of the hypotenuse?
25
True or False: All angles in a right triangle are acute.
False
What is the formula for finding the length of a leg given the hypotenuse and the other leg?
Leg = √(Hypotenuse² - Other Leg²)
Fill in the blank: A right triangle with angles of 30, 60, and 90 degrees is known as a ______ triangle.
special
What is the tangent of a 90-degree angle?
Undefined
If the opposite side is 5 and the adjacent side is 12, what is the tangent of the angle?
5/12
True or False: The legs of a right triangle can be of different lengths.
True
What is the sine of an angle if the opposite side is 8 and the hypotenuse is 10?
0.8
Fill in the blank: The cosine of an angle is equal to the length of the ______ side divided by the length of the hypotenuse.
adjacent
What is the value of the sine of 0 degrees?
0
What is the length of the adjacent side if the hypotenuse is 15 and the opposite side is 9?
12
True or False: In a 45-45-90 triangle, the legs are equal.
True
What is the area of a right triangle with legs of length 6 and 8?
24
What is the cosine of a 90-degree angle?
0
Fill in the blank: The formula for the Law of Sines is ______.
(a/sin(A)) = (b/sin(B)) = (c/sin(C))
What is the tangent of a 0-degree angle?
0
If one leg of a right triangle is 9 and the hypotenuse is 15, what is the length of the other leg?
12
True or False: The angles in a right triangle can be negative.
False
What is the sine of 60 degrees?
√3/2
What is the cosine of 0 degrees?
1
Fill in the blank: The tangent of an angle can be found using the formula ______.
opposite/adjacent
What is the length of the hypotenuse if one leg is 7 and the other leg is 24?
25
True or False: The Pythagorean theorem can only be used in right triangles.
True
What is the sine of 45 degrees?
√2/2
What is the cosine of 30 degrees?
√3/2
Fill in the blank: The opposite side is opposite to the ______ of the angle.
vertex
What is the area of a right triangle with a base of 10 and a height of 5?
25
What is the tangent of 45 degrees?
1
If the hypotenuse is 10 and one leg is 6, what is the length of the other leg?
√64 or 8
True or False: The angles in a triangle can exceed 180 degrees.
False
What is the sine of 90 degrees?
1