Formulas
What is the formula used to find the perimeter of a rectangle or square?
Perimeter = Length + Length + Width + Width
OR
Perimeter = Side + Side + Side + Side
What is the perimeter of a rectangular garden that is 10 feet long and 5 feet wide?
10 ft + 10 ft + 5 ft + 5 ft = 30 ft
A triangle has sides that measure 5 cm, 7 cm, and 10 cm. What is its perimeter?
22 cm
Farmer Joe needs to build a fence around a rectangular yard that is 12 meters by 8 meters. How much fencing will he need?
12 m + 12 m + 8 m + 8 m =
24 m + 16 m =
40 m
He needs 40 meters of fencing
What is the formula used to find the perimeter of a triangle?
Perimeter = Length + Width + Height
OR
Perimeter = Side + Side + Side
A square sticky note has a side length of 3 in. What is its area?
3 in x 3in = 9in2
What is the area of a triangle with a base of 6 inches and a height of 4 inches?
(6 in x 4in) / 2 =
24 in2 / 2 =
12 in2
100 yd / 4 =
25 yd
What is the formula used to find the area of a rectangle or square?
Area = Length x Width
A rectangle has an area of 48 cm2. If the length is 8cm, what is the width?
48cm2 / 8 cm = 6cm
What is the area of a right triangle that has a base of 10 meters and a height of 5 meters?
(10m x 5 m) / 2 =
50m2 / 2 =
25m2
Maya wants to put a wood boarder around a rectangular photo and cover it with glass. The photo is 5 in by 7 in. How much wood and glass would she need?
Wood - 5 in + 5 in + 7 in + 7 in = 24 in of wood
Glass- 5 in x 7 in = 35 in2 of glass
What is the formula used to find the area of a triangle?
Area = (Base x Height) / 2
OR
Area = (Base x Height) x 1/2
A rectangular rug has a perimeter of 20 ft. If the width is 4 ft, what is the length?
[20 ft - (4ft + 4ft)] / 2 =
[20 ft - 8ft] / 2 =
12 ft / 2 =
6 ft
A local park is designing a new flower bed in the shape of a right triangle to fit into a corner of the plaza. The landscapers determine that the base of the triangle measures 12.4 meters and the height measures 8.2 meters. What is the area of the flower bed?
Area = (Base x Height) / 2
Area = (12.4 m x 8.2 m) / 2
Area = 101.68 m2/ 2
Area = 50.84 m2
A painter needs to cover a triangular wall section with a base of 8 feet and a height of 10 feet. How many square feet will he end up painting?
(8 ft x 10 ft) / 2
80 ft2 / 2
40 ft2
What is the formula used to find the volume of a rectangular prism?
Volume = Length x Width x Height
If you double both the length and width of a rectangle, the area increases by how many times?
The area will increase by 4 times
An artist is creating a triangle shaped stained-glass piece and needs to cover the edges with metal so they are not sharp. The sides of the triangle are 5 1/2 in, 4 1/4in, and 6 3/4 in. How many inches of metal does the artist need to buy to cover all of the edges?
Perimeter = 5 1/2 in + 4 1/4 in + 6 3/4 in
Perimeter = 5 2/4 in + 4 1/4 in + 6 3/4 in
Perimeter = 15 6/4 inches
Perimeter = 16 2/4 inches
The artist needs to bu 16 1/2 inches of metal
A rectangular pool has an area of 200 ft2. If the length is twice the width, what are the dimensions of the pool?
A = Length x Width
200 ft2 = Length x Width
Length = Width x 2
200 ft2 = (2Width) x Width
200 ft2 = 2 x Width2
100 ft2 =Width2
10 ft = Width