X2 - 17x + 72
=(x - 9)(x - 8)
if x = 20 the length of the rectangle is 12 units and width 11 units.
A. An organ is the oldest keyboard instrument.
The sum of all exterior angles of ANY polygon is equal to 360 degrees.
SO in this figure...
360 = 134 + 130 + x
360 = 264 + x
x = 360 - 264 = 96 degrees
Hi,
The answer will be

.
Now how is that, there is a rule for the right angled triangle which says:
cosθ =

so, if we applied this rule on the lower triangle we can say: cos30°=

and therefore the hypotenuse =

=

.
now in the upper triangle we will apply the same rule so,
cos45°=

and the adjacent side in the upper triangle is

and the hypotenuse is x.
so cos45°=

and then we can say
x=

=

.