All about Geometry

by Samantha W

Angles types

There are four angles! Right, obtuse,acute straight. A Right angle is 90 degrees exactly. A obtuse angle is more 90 degrees less than 180 degrees. Acute angle is less than 90 degrees. A straight angle is 180 degrees exactly.


Triangle types

There are six triangle types. Acute triangle , Obtuse triangle, Right triangle , Scalene triangle , Isosceles trirangle , Equilateral triangle. A Acute triangle has three acute angles. A Obtuse triangle has one obtuse angle and two acute angles. A Right triangle has one right angle and two acute angles. A Scalene triangle has 0 congruent sides and 0 congruent angles. A Isosceles triangle has two congruent sides and two congruent angles. A Equilateral triangle has three congruent sides and three congruent angles.

Quadrilateral types

There are five quadrilateral types . Parallelogram, Rectangle, square, Rhombus, Trapezoid. A Parallelogram has opposite sides congruent, opposite angles congruent, opposite sides parallel. A Rectangle has opposite sides parallel, all FOUR angles are RIGHT, opposite sides congruent. A Square has opposite sides parallel, ALL sides congruent, opposite angles congruent. A Rhombus ALL angles RIGHT, opposite sides parallel, ALL sides are congruent. A Trapezoid has EXACTLY ONE pair of parallel sides.