Area of a Triangle: Subtraction or addition to a larger shape

The quadrilateral ABCD is a rectangle.

Points E and F are located on sides DC and BC respectively.

FC = 1.5 cm
EC = 5 cm
DE = 3 cm

AD = 4 cm

Calculate the area of the quadrilateral ABFE.

Let's calculate the side DC:

$3+5=8$

Now we can calculate the area of square ABCD:

$4\times8=32$

Let's calculate the area of triangle ADE:

$\frac{4\times3}{2}=\frac{12}{2}=6$

Let's calculate the area of triangle FCE:

$\frac{5\times1.5}{2}=\frac{7.5}{2}=3.75$

Now let's calculate the area of AEFB by subtracting the other areas we found:

$AEFB=32-6-3.75=22.25$

22.25

Below is the trapezoid ABCD.

AB = 5 cm

DC = 10 cm

EC = 2 cm

AF = 4 cm
AF is perpendicular to DC.

Calculate the area of the quadrilateral ABCE.

14

Given the triangle ABC whose area is 95 cm².

Given DFBE parallelogram
DH is the height of the triangle AFD

AB=13 DH=6 AF=5

What is the area of the triangle DEC?

32 cm²

In a square-shaped recreation space, they want to paint part of it white so that the shape of the white paint is triangular.

The length of the play area is 6 meters

one box of paint is required for each meter of paint.

How many buckets of paint do you need to paint the triangular area?

18 paint boxes

The shape below consists of a rectangle from which the line segment BH has been erased.

AB = 6 cm

AH = 7 cm

EF = 3 cm

HG = 12 cm

BC = 3 cm

Calculate the area of the shape shaded orange.

43.5 cm

The drawing shows an equilateral triangle

The length of each of its sides 7 cm

a semicircle is placed on each side of each side

What is the area of the entire shape? Replace $\pi=3.14$

78.91 cm².