Types of Geometric Figures
There are tons of different geometric figures, from circles with no sides to figures that have too many sides to count. During 7th grade math, you will mostly deal with triangles and quadrilaterals, although you may see a few other basic shapes. See below for specific types of figures.
TRIANGLES
Triangles classified by their angles:
![Picture](/uploads/2/0/1/1/20114429/1624440.jpg?1369067370)
Acute Triangles are triangles whose internal angles all measure less than 90 degrees.
![Picture](/uploads/2/0/1/1/20114429/2615816.jpg)
Right Triangles are triangles who have ONE angle that is exactly 90 degrees, also known as a right angle.
![Picture](/uploads/2/0/1/1/20114429/3955699.jpg)
Obtuse triangles are triangles who have ONE angle that is greater than 90 degrees but less than 180 degrees, also known as an obtuse angle.
Triangles classified by their side lengths:
![Picture](/uploads/2/0/1/1/20114429/5013767.jpg)
Scalene Triangles are triangles who have 3 different side lengths. None of their side lengths are the same.
![Picture](/uploads/2/0/1/1/20114429/512410.jpg)
Isosceles Triangles are triangles who have 2 side lengths that are the same. This means that 2 of their interior angles are also the same.
![Picture](/uploads/2/0/1/1/20114429/9393148.jpg)
Equilateral Triangles are triangles whose side lengths are all congruent. This means that all of the interior angles of the triangle are 60 degrees.
QUADRILATERALS
![Picture](/uploads/2/0/1/1/20114429/5702798.jpg)
A quadrilateral is any 4 sided figure.
![Picture](/uploads/2/0/1/1/20114429/6045597.jpg)
A parallelogram is a quadrilateral whose opposide sides are parallel and are congruent (the same length).
![Picture](/uploads/2/0/1/1/20114429/4669533.jpg)
A rectangle fits the properties of a parallelogram but also has 4 right angles (90 degrees).
![Picture](/uploads/2/0/1/1/20114429/2711954.jpg?1369144437)
A rhombus fist all of the properties of a parallelogram, but all 4 of its sides are congruent (the same length).
![Picture](/uploads/2/0/1/1/20114429/3201553.jpg)
A square meets all of the properties of a parallelogram, a rectangle and a rhombus. This means that a square:
-Has opposite sides that are parallel and congruent (the same length)
-Has 4 right angles (90 degrees)
-Has 4 sides that are all congruent (the same length)
-Has opposite sides that are parallel and congruent (the same length)
-Has 4 right angles (90 degrees)
-Has 4 sides that are all congruent (the same length)
![Picture](/uploads/2/0/1/1/20114429/1370230182.jpg)
Trapezoids have exactly one pair of opposite sides that are parallel. These opposite parallel sides are called bases. The sides that are not parallel are called legs.