Question

write all basic formulas of geomatry class 8. 9. 10
please I will give u 20 points

Answer 1

Basic Geometry Formulas

PerimeterofaSquare=P=4a

Where a = Length of the sides of a Square

PerimeterofaRectangle=P=2(l+b)

Where, l = Length ; b = Breadth

AreaofaSquare=A=a2

Where a = Length of the sides of a Square

AreaofaRectangle=A=l×b

Where, l = Length ; b = Breadth

AreaofaTriangle=A=b×h2

Where, b = base of the triangle ; h = height of the triangle

AreaofaTrapezoid=A=(b1+b2)h2

Where, b1 & b2 are the bases of the Trapezoid ; h = height of the Trapezoid

AreaofaCircle=A=π×r2
CircumferenceofaCircle=A=2πr

Where, r = Radius of the Circle

SurfaceAreaofaCube=S=6a2

Where, a = Length of the sides of a Cube

SurfaceAreaofaCylinder=S=2πrh

VolumeofaCylinder=V=πr2h

Where, r = Radius of the base of the Cylinder ; h = Height of the Cylinder

SurfaceAreaofaCone=S=πr(r+h2+r2−−−−−−√)

VolumeofaCone=V=πr2h

Where, r = Radius of the base of the Cone, h = Height of the Cone

SurfaceAreaofaSphere=S=4πr2

VolumeofaSphere=V=43πr3

Where, r = Radius of the Sphere

Answer 2

perimeter of square equal to 4a
" " rectangle =2(l+b)
area of square = side×side
area of rectangle = l×b
volume = length ×breadth × height
length in volume equal to volume / breadth into height
breadth in volume equal to volume / length into height
height in volume equal to volume\ length into breadth
volume of square equal to length into length
into length
Volume of Cylinder equal to pirsquareh