Circumference of a square = side length ×4 Formula: C=4a

Square area = side length × side length formula: s = a× a.

Cube volume = side length × side length × side length formula: v = a× a× a.

2. Square

The circumference of a rectangle = (length+width) ×2 Formula: C=(a+b)×2.

Area of rectangle = length× width formula: S=a×b

Cuboid volume = length× width× height formula: v = a× b× h.

Step 3: Triangle

Area of triangle = base × height ÷2. Formula: S= a×h÷2.

4. Parallelogram

Area of parallelogram = base× height formula: S= a×h

5. trapezoidal

Trapezoidal area = (upper bottom+lower bottom) × height ÷2 Formula: S=(a+b)h÷2.

6. circle

Diameter = radius ×2 Formula: d=2r

Radius = Diameter ÷2 Formula: r= d÷2

Circumference = π× diameter formula: c=πd =2πr

Area of circle = radius × radius× π formula: s = π RR.

7. Cylinder

Transverse area of cylinder = bottom circumference × height. Formula: s = ch = π dh = 2π rh.

Surface area of cylinder = perimeter of bottom × height+area of circles at both ends. Formula: S=ch+2s=ch+2πr2.

Total volume of cylinder = bottom area × height. Formula: V=Sh

8. Cone

Total volume of cone = bottom area × height × 1/3 formula: V= 1/3Sh.

The sum of the internal angles of the triangle = 180 degrees.

Parallel lines: Two straight lines that do not intersect the same plane are called parallel lines.

Perpendicular: Two straight lines intersect at right angles. Two straight lines like this,

Suppose these two straight lines are perpendicular to each other, one of which is called the perpendicular of the other, and the intersection of these two straight lines is called the vertical foot.