Chapter 8 Review

8-1 The Pythagorean Theorem

You must remember the Pythagorean Theorem a² + b² = c² and that it only works on right triangles.

You must also be able to identify triangles as being acute, right, or obtuse. If c² > a² + b² then it is obtuse. If c² ˂ a² + b² then it is acute.

Practice problems Page 420 1-6all, 10-15all, 18-29all

8-2 Special Right Triangles

45-45-90 triangles s√2 s s 30-60-90 triangles 2s s s√3 Practice problems Page 428 1-6all, 9-

14all, 17-22all

8-3 The tangent Ratio

You need to know the Tangent Ratio Remember this trig function only works on right

triangles If I ask for a ratio, I only want a fraction but make sure

it is in simplest terms (reduce it) Tan∠ = opposite/adjacent If you are trying to find an angle then you use ta n0,which is tangent inverse.¹ You need to decide, based on the given information which trig function to use and what order to put the information in. Make sure you have a calculator that has trig functions on it and know how to use it. Practice problems Page 434 1-9all, 11-20all, 27-29all.

8-4 Sine & Cosine Ratios

You need to know both the Sine and the Cosine Ratios Remember that these trig functions only work on right

triangles If I ask for a ratio, I only want a fraction but make sure it is

in simplest terms (reduce it) Sine (sin) Sin∠ = opposite/hypotenuse Cosine (cos) Cos∠ = adjacent/hypotenuse If you are trying to find an angle, then you would use either sin or cos , which is sine inverse or cosine inverse, ⁻¹ ⁻¹respectively You have to decide, based on the information given which trig function to use and what order to put the information in Make sure you have a calculator that has trig functions on it and know how to use it Practice problems Page 441 1-9all, 11-16all, 22-24all

8-5 Angles of Elevation & Depression

An angle of elevation is from the point of view the object has. So, if the object is looking up then it is an angle of elevation

An angle of depression is from the point of view the object has. So, if the object is looking down then it is an angle of depression

It helps that the lines are parallel because then the angles are alternate interior which means that they are congruent. You can then figure out the measurements of the missing side using the trig functions that you just learned

Practice problems Page 447 1-10all, 12, 13