Answer:
1. AC is perpendicular to BD
1. Given
2. ACB is a right angle
2. Definition of perpendicular lines
3. Triangle ACB is a right triangle
3. Definition of right triangles
4. Angles 1 and 3 are complementary
4. Interior angles of a triangle add up to 180 degrees (Triangle Interior Angle Sum Theorem), and m<ACB = 90 degrees (definition of right angles), so m<1 + m<3 = 90 degrees (subtraction property of equality). By the definition of complementary angles, angles 1 and 3 are complementary.
Answer:
(C)4
Step-by-step explanation:
Given the line: 
The gradient of the line, 
A line perpendicular to the given line will have a gradient,
(by definition of perpendicularity).
Therefore, a perpendicular line that passes through the point (4,1) is:

Comparing with the slope-intercept form y=mx+x, the slope of the perpendicular line, b=4.
Answer:
B
Step-by-step explanation:
Domain is basically x. The left side is connecting with the right side (y).
this is why the domain is B
Hope this helps!
Answer:
Exact form: x = + 7 sqaureroot 2
Decimal Form: x = 9.89