angle
background
board
centimeter
chalk
chalkboard
closeup
college
color
degrees
design
drafting
drawing
education
engineering
equipment
female
geometry
green
hands
item
knowledge
learn
learning
length
line
markings
math
mathematical
mathematics
measure
measurement
measuring
number
person
protractor
ruler
school
science
shape
stationery
study
supplies
teach
tool
triangle
university
woman
work