Find the value of x in a triangle. x-20, x+10, x-20

The value of the angles should be. (x-40°). , (x-20°), (½x-10°) , not (x-40°) + (x-20°)+(½x-10°)

Sum of all the interior angles of a triangle is 180°.

So a equation can be made by the given data,

(x-40°) + (x-20°) + (½ x-10°) = 180°

x-40°+x-20°+½x-10° = 180°

2x+½x -60°-10° = 180°

5/2 x - 70° = 180°

5/2 x = 180° + 70°

5/2 x = 250°

x = 250° × 2/5

x = 50° × 2

x = 100°

So the angles are

x-40° = 100°-40° = 60°

x-20° = 100°–20° = 80°

½x-10° = ½(100)° - 10° = 50° -10° = 40°

The answer can be checked by putting the values of the angle we got in the second statement i.e. Sum of all the interior angles of a triangle is 180°.

60° + 80° + 40° = 100° + 80° = 180°

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

/

step-by-step explanation: