This type of triangle has all equal sides and equal angles
EQUILATERAL TRIANGLE
All angles of a triangle add up to _______ degrees.
180
What tools do you need to make a construction?
Ruler and compass.
Same side interior angles are complimentary.
Solve for x: 47 + 92 + x = 180
x = 41
Fill in the blanks:
Complementary angles are equal to ____ degrees.
Supplementary angles are equal to ____ degrees.
Complementary angles are equal to 90 degrees.
Supplementary angles are equal to 180 degrees.
What is true about isosceles tiangles?
They have two equal sides and therefore, two equal angles.
What does a bisector do?
Cuts something (angle or line) into two equal halves.
What is the relationship between corresponding angles?
Corresponding angles are equal to each other.
Solve for a: a + 24 + a = 90
a = 33
This "third" parallel line helps solve for unknown angles.
AUXILLARY LINE
What is the angle measure of an equilateral triangle?
60 degrees
Using your compass and a straight edge, construct a perpendicular bisector to this line segment.
Solve for a, b, and c.
a = 53
b = 53
c = 117
Solve for x
x = 85
What are two angles that have the same vertex and share a side in common (angles that are next to each other)?
Adjacent Angles
Solve for x.
x = 120
Starting from this line segment, use your compass and straight edge to construct an equilateral triangle.
What is the relationship between alternate interior angles?
Congruent
Solve for x.
x = 14
The exterior angle theorem states that the exterior angle of a triangle equals the sum of what?
The two opposite interior angles.
Why does the exterior angle theorem make sense?
The total sum of a triangle is 180. The total sum on a line equals 180.
Using your compass and straight edge, construct an angle bisector.
What is the relationship between alternate exterior angles?
Congruent
Solve for x and y.
x = 30
y = 90