Answer:
see explanation
Step-by-step explanation:
(a)
(the side required )² = sum of squares of other 2 sides - ( 2 × product of other 2 sides and cos(angle opposite side required ) )
x² = 12² + 15² - (2 × 12 × 15 × cos71°)
(b)
x² = 144 + 225 - 360cos71°
= 369 - 360cos71° ( take square root of both sides )
x = 
≈ 16 cm ( to the nearest integer )
Equation of line is doubling
ANSWER

EXPLANATION
The given line passes through;
(-1,-1) and it is parallel to x + y = 3.
This line given to us can be rewritten as
y=-x+1
It has slope m=-1.
The line parallel to this line also has slope m=-1.
We obtain the equation of the line using the formula:

We substitute the slope and the point to obtain:



The equation of the line is

Step-by-step explanation:
-7.6x+7.4-3.5x-6.5
-7.6x-3.5x+7.4-6.5
-11.1x+0.9
Step-by-step explanation:
Gradient of line AB = 6/2 = 3.
Gradient of line CD = 10/2 = 5.
Gradient of line AD = 12/8 = 1.5.