Angles & Triangles Flashcards
What is a right angle
One that equals 90º
What is an Acute Angle?
One less than 90º
What is an obtuse angle?
One that is more than 90º but less than 180º
What is a straight angle?
One that is 180º exactly
What is a reflex angle?
One that is more than 180º but less than 360º
What are supplementary angles?
Two angles than total 180º when put together
What are complementary angles?
Two angles that total 90º when put together
Will a line that cuts through two or more parallel lines create sets of matching angles?
Yes
What are vertical angles?
The vis-á-vis angles that are created when two lines cross
These angles will be equal
A triangle is a ______ with three sides.
Polygon
A triangle’s angles sum to _____º.
180º
The altitude of a triangle is its ______.
Height
The base of the triangle is its ______.
Length
The perimeter of a triangle is ________.
The sum of it’s three sides
The area of a triangle is _______.
½(base x height)
What is the angle bisector of a triangle?
A line that bisects an angle in a triangle
What is a triangle’s median?
A line drawn from any angle in a triangle to the midpoint of the opposite side
What is a scalene triangle?
One with unequal angles and unequal sides
What is an isosceles triangle?
One with at least two equal sides
An isosceles triangle will have _____ angles.
Two equal
The two equal angles in an isosceles triangle are called the ______ angles. The other angle is called the ______ angle.
Base
Vertex
What is an equilateral triangle?
One where all the sides are the same
What is the size of the angles in an equilateral triangle?
60º
What is the perimeter of an equilateral triangle?
3(side)
What is the area of an equilateral triangle?
4
What is the hypotenuse of a triangle?
The side opposite the right angle
What is an obtuse triangle?
One with one obtuse angle
What is an exterior angle of a triangle?
The angle created by extending on side
The sum of any two sides of a triangle must be __________.
Greater than the third side
The largest angle of a triangle will lie opposite to its ___________.
Largest side
A side of a triangle must be _____ and _____ of the other two sides.
Greater than the difference
Less than the sum
What is the Pythagorean Theorem?
For right triangles, the hypotenuse squared equals the sum the othe squares of the other sides.
c² = a² + b²
Two angles that add up to 90 degrees are called _______.
Two angles that add up to 180 degrees are called _______.
Complementary Angles
Supplementary Angles
