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)
