11/12 FLASHCARD

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures greater than 90 degrees but less than 180 degrees.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

How do you determine if a triangle is obtuse, acute, or right based on its side lengths?

Back

Use the Pythagorean theorem: If c^2 > a^2 + b^2, the triangle is obtuse; if c^2 < a^2 + b^2, it is acute; if c^2 = a^2 + b^2, it is right.

Front

What is the formula for the area of a triangle?

Back

The area of a triangle can be calculated using the formula: Area = 1/2 * base * height.

Front

What is the relationship between the angles in a triangle?

Back

The sum of the interior angles in a triangle is always 180 degrees.

Front

What is the significance of the side lengths in determining the type of triangle?

Back

The side lengths determine the type of triangle: equilateral (all sides equal), isosceles (two sides equal), or scalene (all sides different).

Front

What is the formula for the sine of an angle in a right triangle?

Back

The sine of an angle is defined as the ratio of the length of the opposite side to the length of the hypotenuse: sin(θ) = opposite/hypotenuse.

Front

What is the formula for the cosine of an angle in a right triangle?

Back

The cosine of an angle is defined as the ratio of the length of the adjacent side to the length of the hypotenuse: cos(θ) = adjacent/hypotenuse.

Front

What is the formula for the tangent of an angle in a right triangle?

Back

The tangent of an angle is defined as the ratio of the length of the opposite side to the length of the adjacent side: tan(θ) = opposite/adjacent.

Front

What is the Law of Cosines?

Back

The Law of Cosines states that for any triangle, c^2 = a^2 + b^2 - 2ab*cos(C), where C is the angle opposite side c.