Question

How do you do this????

Answer 1

Area = 5.3

Explanation:

Step One

Find BE

• Area ΔABC = 15
• Area = 1/2 AC * h = 1/2 AC * BE
• 15 = 1/2 * 5 * BE
• 30 = 5*BE
• 30/5 = BE
• BE = 6

Step Two

Find s

The second thing you must do is realize that if you have the length of 3 sides you can use Heron's formula

s = 1/2(a + b + c)

• a = 3
• b = 4
• c = 6

• s = 1/2 * (3 + 4 + 6)
• s = 1/2 * 13
• s = 6.5

Step Three

Find the area of BDE

Formula

Area = sqrt(s * (s - a)(s - b)(s - c)

Solution

• s = 6.5
• s - a = 6.5 - 6 = 0.5
• s - b = 6.5 - 4 = 2.5
• s - c = 6.5 - 3 = 3.5

• Area = sqrt(6.5 * 0.5 * 2.5 * 3.5)
• Area = sqrt(28.4375)
• Area = 5.333 which when rounded is 5.3