## 7th Grade Properties and Formulas

Angle and Side Properties:  draw a sample picture to help you remember!

·       triangle = 180 degrees
·
quadrilateral = 360 degrees
(lines will touch one another eventually)

·
parallelograms: opposite sides
are parallel and congruent

·
rectangles:  90 degree angles and
opposite sides are congruent

·
rhombi: all sides same length,
opposite angles are congruent

·
squares:  angles are 90 degrees,
all sides congruent

·
trapezoids: (very similar to a quadrilateral)
one pair of opposite sides are parallel the other pair is NOT

Formulas
1.  PERIMETER: add up all sides or 2l + 2w

2.  AREA: l x w (answer is always squared)

3.  CIRCUMFERENCE OF CIRCLE:

~d (if give diameter)

2~r (if give radius)

4. AREA OF PARALLELOGRAM: A=bh

5.  AREA OF TRIANGLE: A=1/2bh

6.  area of Trapezoid: A=1/2h(b + B)

7.  area of circle: A= ~

8.  area of semicircle: A=

area is always :  squared

volume is always :  cubed

PEMDAS: Parenthesis, exponents, multiplication and division, addition and subtraction