Question

ABC and DEC are right triangles

Answer 1

first find the side EC by setting up ratio. use pythagorean theorem to find the hypotenuse side.

Answer 2

Area of triangle DEC = 18.9 square feet

Explanation:

Here triangle ABC and DEC are similar triangles.

By similar triangle property,

AB/DE = BE/EC -----------------------(1)

Since AB=20 feet, DE =6 feet and BE = 21 feet , we need to find EC.

So, Plug these values in the equation (1)

We get, 20/6 = 21/EC

EC = 21*6 / 20 = 6.3 feet

Now,we will find area of triangle DEC.

area = 1/2 bh ,

Here b = EC = 6.3 feet

And h = DE = 6 feet

So, Area of triangle DEC = 1/2 * 6.3 * 6 = 18.9 square feet