Front

Area of a rectangle

Back

A = l × w

Front

Perimeter of a rectangle

Back

P = 2(l + w)

Front

Area of a square

Back

A = s²

Front

Perimeter of a square

Back

P = 4s

Front

Area of a triangle

Back

A = 1/2 × b × h

Front

Perimeter of a triangle

Back

P = a + b + c

Front

Area of a parallelogram

Back

A = b × h

Front

Perimeter of a parallelogram

Back

P = 2(a + b) or add up all the sides

Front

Area of a trapezoid

Back

A = 1/2 × (b₁ + b₂) × h

Front

Circumference of a circle

Back

C = 2πr

C = πd