4.1-4.4 Flashcard Review

Front

What does the Third Angles Theorem state?

Back

If two angles of one triangle are congruent to two angles of another triangle, then the third angles are also congruent.

Front

How do you determine if a triangle is acute, right, or obtuse?

Back

A triangle is acute if all angles are less than 90°, right if one angle is exactly 90°, and obtuse if one angle is greater than 90°.

Front

Solve for x: 2x + 4 = 28.

Back

x = 12.

Front

What does it mean when two triangles are congruent (∆ABC≅∆XYZ)?

Back

It means that all corresponding sides and angles of the triangles are equal.

Front

What is a reflection in geometry?

Back

A reflection is a transformation that flips a figure over a line, creating a mirror image.

Front

What is the sum of the interior angles of a triangle?

Back

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

Front

Define an acute triangle.

Back

An acute triangle is a triangle where all three angles are less than 90°.

Front

What is the formula for finding the area of a triangle?

Back

Area = 1/2 * base * height.

Front

What is the Pythagorean theorem?

Back

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 (a² + b² = c²).

Front

How do you find the value of x in a triangle using the exterior angle theorem?

Back

The exterior angle is equal to the sum of the two opposite interior angles.