# Grade 4 - Geometry (Lessons 4-5)

## 20 terms

### Circle

closed plane figure made up of all the points that are the same distance from the center

any line segment that connects the center to a point on the circle

### Diameter

any line segment through the center that connects 2 points on a circle

### Chord

any line segment that connects 2 points on a circle

360°

### Center of a Circle

point in the middle of the circle

### Isosceles Triangle (named for its sides)

a triangle with at least 2 sides the same length

### Scalene Triangle (named for its sides)

a triangle with none of its sides the same length

### Equilateral Triangle (named for its sides)

a triangle with all sides that are the same length

### Right Triangle (named for its angles)

a triangle with 1 angle equal to a right angle (90°)

### Acute Triangle (named for its angles)

a triangle where all 3 angles are acute (less than 90°)

### Obtuse Triangle (named for its angles)

a triangle where 1 angle is obtuse (greater than 90°)

### What is the sum of all the angles in a triangle?

180°

Named by their angles or pairs of sides

### Parallelogram

quadrilateral with both pairs of opposite sides parallel

### Trapezoid

quadrilateral with 1 pair of parallel sides (the other sides will intersect)

### Rectangle

parallelogram (quadril) with 4 right angles

### Square

parallelogram (quadril) with 4 right angles and all 4 sides are the same length

### Rhombus

parallelogram (quadril) with 4 sides the same length (slanted square)

### What is the sum of all the angles in a quadrilateral?

360° is the sum of the angles in a quadrilateral