Sagot :
Just add all the sides! And you will get the perimeter!
Triangle:
side + another side + another side
Regular Triangle:
3s
Square:
4s
Rectangle:
2l + 2w
Rhombus:
4s
Octagon:
side+another side+another side+another side+another side+another side+another side+another side
Regular Octagon:
8s
Heptagon
side+another side+another side+another side+another side+another side+another side
Regular Heptagon:
7s
Equilateral Triangle:
3s
Triangle:
side + another side + another side
Regular Triangle:
3s
Square:
4s
Rectangle:
2l + 2w
Rhombus:
4s
Octagon:
side+another side+another side+another side+another side+another side+another side+another side
Regular Octagon:
8s
Heptagon
side+another side+another side+another side+another side+another side+another side
Regular Heptagon:
7s
Equilateral Triangle:
3s
triangle- S1 + S2 +S3 or SX3 ( if it is a regular)
square-SX4 or S1+S2+S3+S4
Rectangle-2L+2W or 2X(L+W)
Rhombus-S1XS2XS3XS4 or SX4
Octagon- (if it is a regular) SX8
(if it is an irregular just add all the sides)
heptagon-(if it is a regular) SX7
(if it is an irregular just add all the sides)
Equilateral triangle-SX3 or S1+S2+S3
-I hope this can help :D
square-SX4 or S1+S2+S3+S4
Rectangle-2L+2W or 2X(L+W)
Rhombus-S1XS2XS3XS4 or SX4
Octagon- (if it is a regular) SX8
(if it is an irregular just add all the sides)
heptagon-(if it is a regular) SX7
(if it is an irregular just add all the sides)
Equilateral triangle-SX3 or S1+S2+S3
-I hope this can help :D