Unit 4 and 5 Review: Triangles, Angles, and Solving Equations

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

What is an acute angle?

Back

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

Front

What is a right angle?

Back

A right angle is an angle that measures exactly 90°.

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90° but less than 180°.

Front

What is the formula for the sum of angles in a polygon?

Back

The sum of the interior angles of a polygon with n sides is given by the formula (n-2) × 180°.

Front

How do you solve for x in the equation 6 + 3(-x + 11) = 3?

Back

First, simplify: 6 + 3(-x) + 33 = 3. Then, combine like terms: 39 - 3x = 3. Finally, isolate x: -3x = 3 - 39, so x = 12.

Front

What does it mean to solve an equation by showing balance?

Back

Solving an equation by showing balance means performing the same operation on both sides of the equation to maintain equality.

Front

What is the value of x in the equation \(\frac{x}{3} + 10 = 15\)?

Back

To solve for x, subtract 10 from both sides: \(\frac{x}{3} = 5\). Then multiply both sides by 3: x = 15.

Front

What is a linear equation?

Back

A linear equation is an equation that makes a straight line when graphed. It has the form y = mx + b, where m is the slope and b is the y-intercept.

Front

What is the definition of complementary angles?

Back

Complementary angles are two angles whose measures add up to 90°.