+0  
 
0
2118
5
avatar

1.) Triangle Abc has a right triangle at C. CD is the altitude to AB. If CD = 6cm, AD = 3cm and DB= 5x - 3cm. Find x, AB, AC and BC.

 

2.) In right triangle ABC, CD is the altitude to the hypotenuse AB. If CD = 3cm and DB exceeds AD by 8cm. Find AD, DB, AB, BC and AC.

 

3.) A man travels 16km north and the 8km west. How far is he from the starting point?

 

4.) Find the side of a rhombus whose diagonals are 10cm and 26cm.

 

5,) The length of a rectangle is 7cm more than its width. If a diagonal measures 17cm. Find the dimensions of the

 

7.) A right triangle has legs a and b and hypotenuse c. Prove that the altitude h to the hypotenuse is h = ab / c.

 Jan 10, 2017
 #1
avatar+129840 
0

1.) Triangle ABC has a right triangle at C. CD is the altitude to AB. If CD = 6cm, AD = 3cm and DB= 5x - 3cm. Find x, AB, AC and BC.

 

ΔADC  ~ ΔACB

AD/DC  = AC/CB

AC  =  √[AD^2 + DC^2 [  = √[ 3^2 + 6^2]  = √45 = 3√5   ...so....

 

AD/DC  = AC/CB

3/6  = [3√5] / [6√5]       so  BC  = 6√5  = √180

 

AC^2  + BC^2  = AB^2

45   + 180  =  AB^2

225  = AB^2

15  = AB

 

AD + DB  = 15

3 + DB  = 15  →   DB   = 12

DB = 12  =  5x - 3  →   15  = 5x  →  x  = 3

 

 

cool cool cool

 Jan 10, 2017
 #2
avatar+129840 
0

7.) A right triangle has legs a and b and hypotenuse c. Prove that the altitude h to the hypotenuse is h = ab / c.

 

The area =  a * b / 2   =   h * c / 2   →    a*b  = c*h  →   h =  ab / c

 

 

cool cool cool

 Jan 10, 2017
 #3
avatar+129840 
0

5,) The length of a rectangle is 7cm more than its width. If a diagonal measures 17cm. Find the dimensions of the

 

W^2  +  [ W + 7]^2  = 17^2

 

W^2  + W^2  + 14W  +  49  = 289

 

2W^2  + 14W  − 240  = 0

 

W^2 + 7W  −  120  = 0

 

(W − 8) (W + 15)  = 0

 

W − 8  = 0       →   W  = 8cm   and L = W + 7  = 8 + 7  = 15cm

 

 

 

cool cool cool

 Jan 10, 2017
 #4
avatar+129840 
0

3.) A man travels 16km north and the 8km west. How far is he from the starting point?

 

√[ 16^2  + 8^2]  = √[256 + 64]  = √ 320  = 8√5 km ≈ 17.89 km

 

 

cool cool cool

 Jan 10, 2017
 #5
avatar+129840 
0

4.) Find the side of a rhombus whose diagonals are 10cm and 26cm.

 

Side  = √[5^2 + 13^2]  = √ [25 + 169]  = √ 194  cm  ≈  13.93 cm

 

 

 

cool cool cool

 Jan 10, 2017

1 Online Users