Examples with solutions for Area of a Deltoid: Using variables

Exercise #1

Given the deltoid ABCD

The main diagonal is equal to 2a+2

Secondary diagonal is equal to a

The area of the deltoid equals 6a

Calculate a a

S=6aS=6aS=6a2a+22a+22a+2aaaAAABBBCCCDDD

Video Solution

Step-by-Step Solution

To solve the question, we first need to remember the formula for the area of a kite:

Diagonal * Diagonal / 2

This means that if we substitute the given data we can see that:

a(2a+2)/2 = area of the kite

Let's remember that we are also given the area, so we'll put that in the equation too

a(2a+2)/2 = 6a

Now we have an equation that we can easily solve.

First, let's get rid of the fraction, so we'll multiply both sides of the equation by 2

a(2a+2)=6a*2
a(2a+2)=12a

Let's expand the parentheses on the left side of the equation

2a²+2a=12a

2a²=10a

Let's divide both sides of the equation by a

2a=10

Let's divide again by 2

a=5

And that's the solution!

Answer

5 cm

Exercise #2

Below is the deltoid ABCD.

Side length BD equals 7 cm.

The area of the deltoid is equal to 98 cm².

What is the value of a? a\text{?} 7772a2a2a5a5a5aAAABBBCCCDDDMMMS=98

Video Solution

Answer

4 4

Exercise #3

Given the deltoid ABCD

height AE formed by the diagonal extension AC

Side length ED equals 3 cm

The area of the deltoid is equal to 189 cm².

Find the value of the parameter

S=189S=189S=1897b7b7b333AAABBBCCCDDDEEE

Video Solution

Answer

9 9

Exercise #4

Given the deltoid ABCD

Side length AC equals 7 cm

The area of the deltoid is equal to 252 cm².

Find the value of the parameter a a S=252S=252S=2527779a9a9aAAABBBCCCDDD

Video Solution

Answer

8 8

Exercise #5

Given the deltoid ABCD

Side length BD equals 8 cm

The area of the deltoid is equal to 180 cm².

Find the value of the parameter a a 8882a2a2a7a7a7aAAABBBCCCDDDMMMS=180

Video Solution

Answer

5 5

Exercise #6

Look at the deltoid ABCD.

The side BD is 13 cm long.

The area of the deltoid is 182 cm².

Calculate a. a\text{.} S=182S=182S=1827a7a7a131313AAABBBCCCDDD

Video Solution

Answer

4 4

Exercise #7

Shown below is the deltoid ABCD.

Side length BD equals 5 cm.

The area of the deltoid is 45 cm².

What is the the value of a? a? 555aaa3a3a3aAAABBBCCCDDDMMMS=45

Video Solution

Answer

4.5 4.5

Exercise #8

Shown below is the deltoid ABCD.

AC = 2X

DB = X

The area of the deltoid is equal to 32 cm².

Calculate DB.

S=32S=32S=322X2X2XXXXAAABBBCCCDDD

Video Solution

Answer

32 \sqrt{32}

Exercise #9

Shown below is the deltoid ABCD.

The diagonal AC = X

Diagonal DB = 5

The area of the deltoid is 20 cm².

Calculate X.

S=20S=20S=20XXX555AAABBBCCCDDD

Video Solution

Answer

x=8

Exercise #10

The deltoid ABCD is shown below.

AC = X

DB = 3X

The area of the deltoid is 27 cm².

Calculate the length of AC.

S=27S=27S=27XXX3X3X3XAAABBBCCCDDD

Video Solution

Answer

18 \sqrt{18}

Exercise #11

ABCD is a deltoid.

Side BM equals 4 cm.

The area of the deltoid is equal to 144 cm².

Calculate b.

2b2b2b4b4b4b444AAABBBCCCDDDMMMS=144

Video Solution

Answer

6 6

Exercise #12

Given the deltoid ABCD

height AE formed by the diagonal extension AC

Side BE equals 5 cm

The area of the deltoid is equal to 160 cm².

Find the value of the parameter b b S=160S=160S=1604b4b4b555AAABBBCCCDDDEEE

Video Solution

Answer

8 8

Exercise #13

Given the deltoid ABCD

Side length MD equals 2 cm

The area of the deltoid is equal to 200 cm².

Find the value of the parameter b b 2b2b2b3b3b3b222AAABBBCCCDDDMMMS=200

Video Solution

Answer

20 20

Exercise #14

Shown below is the deltoid ABCD.

Side length MD equals 3 cm.

The area of the deltoid is 180 cm².

What is the value of b? b\text{?} bbb3b3b3b333AAABBBCCCDDDMMMS=180

Video Solution

Answer

15 15