The three little lines through the sides of the triangle mean all three sides are equal. Because all three sides are equal the three inside angles would aso be equal.
The three angles of a triangle need to equal 180, so we can divide 180 by 3 to find what each angle is:
180 / 3 = 60.
Now we can set the equation with x in it to equal 60:
7x +4 = 60
Subtract 4 from each side:
7x = 56
Divide each side by 7:
x = 56 / 7
x = 8
Answer:
Domain : 0° < x <90°
Range: 90° < y < 180°.
Step-by-step explanation:
When we have a function:
f(x) = y
the domain is the set of the possible values of x, and the range is the set of the possible values of y.
In this case we have:
x + y = 180°
such that x < y
Let's analyze the possible values of x.
The smallest possible value of x must be larger than 0°, as we are workin with suplementary angles.
Knowing this, we can find the maximum value for y:
0° + y = 180°
y = 180° is the maximum of the range.
Then we have:
0° < x
y < 180°
To find the other extreme, we can use the other relation:
x < y.
Then, we can impose that x = y (this value will not be either in the range nor the domain)
if x = y then:
x + y = x + x = 180
2*x = 180
x = 90°
This will be the maximum of the domain and the minimum of the range.
Then we have that the domain is:
0° < x <90°
And the range is:
90° < y < 180°.
