# math chap 8 lessons1-4 vocab

## 21 terms

### perpendicular lines

2 lines that intersect at a right angle

### parallel lines

2 lines in the same plan that do not intersect ever

### acute angle

measures less that 90

= 90

### obtuse angle

measures greater that 90 and less than 180

### acute triangle

has 3 acute angles trianle

### right triangle

has 1 right angle tiangle

### obtuse triangle

has 1 obtuse angle triangle

### equilateral triangle

3 sides of equal lenghth triangle

### isoscels triangle

has 2 equal sides in lenghth triangle

### scalene triangle

no sides of = lenghth triangle

### trapezoid

a quadrilateral with exactly 1 pair of parallel sides

### parallelogram

a quadrilateral with 2 sides of parrallel sides

### rhombus

a parallelogram with 4 sides of = lenghth

### rectangle

a parallelogram with 4 right angles

### square

a parallelogram with 4 sides of = lenghth and 4 right angles

### polygon

a closed figure whose sides are line segments that intersect only at there endpoints

### regular polygon

all the angles have the same measure and all the sides have the same lenghth

measures = 180

### supplementary

the sum of there measures = 180

### complementary

the sum of ther measures = 90