# 3rd Grade Geometry

## 32 terms

### solid figure

a geometric figure that has length, width, and height

### rectangular prism

a solid figure with faces that are rectangles

### cube

a solid figure with 6 faces that are congruent squares

### pyramid

a solid figure whose base is a polygon and whose faces are triangles with a common point

### cylinder

a solid figure with 2 congruent circles as bases

### cone

a solid figure with a circle as its base and a curved surface that meets at a point

### sphere

a solid figure in the shape of a ball

### face

each flat surface on a geometric solid

### edge

a line segment where 2 faces of a solid figure meet

### vertex (plural, vertices)

the corner where 3 or more edges meet

### point

an exact position often marked by a dot

### line

a straight path of points that is endless in both directions

### triangle

a polygon with 3 sides

### polygon

a closed figure made up of straight line segments

### side

a line segment forming part of a polygon

### ray

a part of a line that has one endpoint and continues endlessly in one direction

### angle

a figure formed by two rays that have the same endpoint

### right angle

an angle that forms a square corner

### acute angle

an angle that measures less than a right angle

### obtuse angle

an angle that measures more than a right angle

### parallel lines

lines that never intersect

### line segment

a part of a line that has 2 endpoints

### quadrilateral

a polygon with 4 sides

### pentagon

a polygon with 5 sides

### hexagon

a polygon with 6 sides

### octagon

a polygon with 8 sides

### intersecting lines

lines that cross at 1 point

### vertex

the point where 2 rays meet to form an angle

### perpendicular

2 lines that intersect to form right angles

### equilateral triangle

a triangle with all sides the same length

### isosceles triangle

a triangle with at least 2 sides the same length

### scalene triangle

a triangle with no sides the same length