Question

13. In ADGE,DG = 8,GE = 17, and DE = 15. What is the length of DF? Round to the nearest hundredth.

Answer 1

Answer:

Step-by-step explanation:

The trick is not to get all caught up in Pythagoras. There is a much simpler way to do it. Find the area of the triangle two different ways. DG and DE are at right angles. That is one way to find area. The other is use the height (DF) and multiply that by the hypotenuse GE.

DG*DE/2 = GE * DF/2            Multiply both sides by 2

DG*DE = GE * DF

DG = 8

DE = 15

GE = 17

8*15 = 17* DF

120 = 17 * DF                         Divide by 17

120/17 = DF

DF = 7.06