Figure abcd is graphed on a coordinate plane.

abcd is an isosceles trapezoid. what is the approximate perimeter of abcd? round to the nearest tenth.

16.5 units
18.9 units
20.9 units
24.0 units

1. BC is 1+3=4 (units)

2. AD is 3+5= 8 (units)

3. Draw the altitude CH from point C, as shown in the figure.

4. Then triangle CHD is a right triangle, with hypothenuse CD, and sides HD and CH.

5. 





6. AB=CD=4.47 because the trapezoid is isosceles.

7. P= BC+AD+AB+CD=4+8+4.47+4.47=20.9 (units)