Geometry Review Math 9

Geometry Review Acute Less than 90 Obtuse Less than 90

Right 90 Straight 180

Complementary Two Angles are Complementary if they add up to 90 degrees Supplementary Two Angles are Supplementary if they add up to 180 degrees.

Angles on a Line Add up to 180.

Angles on a Point These angles add up to 360. Which angles are complimentary to BRU?  HRU and PRC

Opposite angles When two lines intersect, four angles are formed. Angles 1 and 3 are called Opposite Angles as are angles 2 and 4. 1 =  3  2 =  4

Pythagorean Theorem PT Rearranged a2 = c2 – b2 b2 = c2 – a2 Used to find the length of sides on triangles that contain an angle that is 90. C is the longest side and called the hypotenuse. It is also directly across the right angle. PT Rearranged a2 = c2 – b2 b2 = c2 – a2

Sum of Interior Angles will equal 180. a + b + c = 180 a c b

Categorized by Angles Acute Right Obtuse All angles are less than 90. Contains a 90 angle. Contains an angle greater than 90.

Categorized by Sides Scalene Isosceles Equilateral Two sides are the same length. All sides are different lengths. All sides are the same length.

Now on to 10.1