Area and Perimeter of Shapes

Question 0

Calculate the perimeter of a square measuring 16 cm each side.

Answer 0

The answer is 64 cm.

Question 1

The Formula for Perimeter of a Square

Answer 1

For example, a square that measures 6 cm in all sides. So how do you get the perimeter of the shape?

The formula(s) for this are either

Side X 4

Or

Side + Side + Side + Side

(Replace Side with the measurement of your square, just get one side’s measurement.)

Question 2

The Formula for Area of a Square

Answer 2

Now that we have done perimeter of a square, let’s move on to the area.

You know square meters of your lot, right? So how do you calculate area of a square?

The formula(s) for that are either:

Side(squared)

Or

Side X Side

Question 3

Calculate the area for a square measuring 9 cm each side.

Answer 3

The answer is 81 cm squared (81 square cm).

Question 4

The Formula for Perimeter of a Rectangle

Answer 4

So how do we get the perimeter of a rectangle?

The formula is as follows:
2l + 2w
(Replace the l and w with the length and width of the shape)

(Length is the longest measuring side.)

You know basic algebra, right?
A letter sticking to a number is automatically multiplication.

So for example, a rectangle measuring 17 mm as length and 9 mm for width.

So replace l and w like this:

2(17 mm) + 2(9mm)

Then multiply them:

34 mm + 18mm

Then add them!

Now you got the perimeter for the rectangle!

Question 5

Calculate the perimeter of a rectangle whose length is 6 m and width is 16 m.

Answer 5

The answer is 44 cm.

Question 6

The Formula for Area of a Rectangle

Answer 6

So we got the formula for calculating the perimeter of a rectangle, what about the area of it?

The formula is as follows:

L X W

(You know what to do on this one.)

Question 7

Calculate the area of a rectangle whose length is 13 dm and width measuring 8 dm.

(dm = dekameter)

Answer 7

The answer is 104 dm squared (104 square dm).

Question 8

The Formula for Perimeter of a Triangle

Answer 8

How do we get the formula for a triangle?

If it’s an equilateral triangle, then do this:
Side X 3

If it’s an isosceles triangle, do this:
Side X 2 + Side C

If it’s a scalene triangle, do this:
Side A + B + C

Question 9

Find the perimeter for an equilateral triangle whose sides are 52 cm.

Find the perimeter for an isosceles triangle whose non-equal side measures 9 cm, while the equal sides measure 17 cm.

Find the perimeter for a scalene triangle whose sides measure 7 cm, 14 cm and 21 cm.

Answer 9

For the equilateral triangle, the answer is 156 cm.

For the isosceles triangle, the answer is 43 cm.

For the scalene triangle, the answer is 42 cm.

Question 10

The Formula for Area of a Triangle

Answer 10

Now that we are familiar with the perimeter for different triangles, let’s move on to the area of it.

So to calculate the area of a triangle, get this formula:

One-half (1/2) Base X Height
(Your base is at side B, the straight line.)
Or just simply:

Base X Height X 0.5

Question 11

Calculate the area of a triangle whose base is 17 inches, and whose height is 9 inches.

Answer 11

The answer is 76.5 inches squared.

Question 12

The Formula for Circumference

Answer 12

So we got the formulas for perimeter and area of sided figures, what about the circle?

The formula(s) you can use are either:
2(phi)r

or

(phi)d.

(Just replace r or d with the radius or diameter.)

If radius is only present, multiply the radius by 2 to get diameter.

If diameter is only present, cut the diameter in half (1/2 of diameter) to get the radius.

(Take 3.14 as the value of phi.)

Question 13

Calculate the circumference whose radius is 8.5 feet.

Answer 13

The answer is 53.38 feet.

Question 14

The Formula for Area of a Circle

Answer 14

So we got the perimeter of the circle, what about its area?

The formula to that is:

phi(radius)squared

(Square the radius first before multiplying phi and radius.)

So: 3.14(6 mm)squared

Question 15

Calculate the area of a circle whose diameter is 24 cm.

Answer 15

The answer is 452.16 cm squared.