From Yahoo Answers

**Question:**For what values of x will the angle below be acute?
It shows a angle with the equation (4x-18) and the equation is in the angle place.

**Answers:**In order for an angle to be acute, it has to be <90 . So:
4x 18 < 90
4x < 108
x < 27
x has to have a measure of less than 27 in order for the angle to be acute.

**Question:**find the equation of two lines that make a 45 degree angle with the graph of the given equation and pass through the given point.
Given: x - y + 3 = 0, (1,4)
i tried to find this online or on youtube, but can't find it ANYWHERE! please help me. I have a quiz on this tomorrow and I have a 80% in that class.

**Answers:**m = 1 ..... the slope of the given line
m = 0 ..... the slope of desired line #1 (at -45 to the given line)
m = inf ... the slope of desired line #2 (at 45 to the given line)
Answer: y = 4 and x = 1

**Question:**what is the supplementary angle measurement of a 145 degrees angle?

**Answers:**I'll answer, but I'll tell you how to do this by steps.
Supplementary angles are angles that equal 180 degrees, so you could think of it as an equation.
145 + x = 180.
Just subtract 145 from 180 and you will get your answer.
Which is 35 degrees.

From Youtube

### Complementary and Supplementary Angles - Example 2

Complementary and Supplementary Angles - Example 2. In this video, I create a system of linear equations to find the measure of an angle knowing information about its complement and supplement.

### Perpendicular Lines and Complementary Angles

Writing equations to solve for complementary angles created by perpendicular lines.

### Trig. Equations : Double Angle Identity Types : (Example 5) : ExamSolutions

In this series of tutorials you are shown several examples on how to solve trig. equations that require the use of the double angle identities. To see the full revision guide goto ExamSolutions at www.examsolutions.co.uk

### Solving angles of triangle using system of equations ( 8 .grade Primary school )

This is a demonstration video that explains how is possible to learn mathematics online trough Skype video call and using graphics tablet and option of sharing screen in Skype . Please comment , make suggestion , maybe you have some wishes about areas of math to be concerned in my next videos ., or you have advices for me to improve my videos . Also , please visit me at : learn-math-and-physics-online.blogspot.com