triangle ABC below has a right angle C and a height CD. (A height in a triangle connects it vertex and the opposite side, and is perpendicular to that side.) If AC is 3 untis long and BC is 4 units long, what is the length of CD?

Respuesta :

9514 1404 393

Answer:

  2.4

Step-by-step explanation:

We can see that this is a 3-4-5 right triangle, so side AB is 5 units long.

The area of the triangle is ...

  A = 1/2bh = 1/2(3 units)(4 units) = 6 units

This is true also when side AB is the base and CD is the height.

 A = 1/2(AB)(CD)

  6 = 1/2(5 units)(CD) . . . . . substitute given information

  6/2.5 = CD = 2.4 . . . . . . . divide by the coefficient of CD

The length of side CD is 2.4 units.

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In the attached, the height to vertex C is given on the bottom line.

Ver imagen sqdancefan