A function and its inverse are shown on the graph. Which statement describes the relationship between the function and its inverse?

The range of both f(x) and f–1(x) is all real numbers.
The domain of both f(x) and f–1(x) is all real numbers.
The range of f(x) is y > 0 and the domain of f–1(x) is x > 0.
The domain of f(x) is x > 0 and the range of f–1(x) is y > 0.

1. 180°. the sum of the interior angles of a triangle is 180°, for the equilateral triangle that it has three equals side is 60°+60°+60°=180°.

2. 60°. each interior angle of a equilateral triangle is 60°

3. 120°. the measure of ∠m is 120°, the sum of the angles ∠m and ∠n is equal to 180°. so, in order to find the measure of ∠m, we have ∠m+∠n=180° > ∠m=180°-∠n > ∠m=180°-60°=120°.

4. 360°. the sum of the exterior angles of an equilateral triangle is ∠m+∠r+∠x=120°+120°+120°=360°. the exterior angles of any triangle always add 360°.