Right Triangle Trig: Finding a missing side

Right Triangle Trig: Finding a missing side

Objective: I will apply my knowledge of right triangles & trigonometry to successfully solve for missing sides of right triangles.

Today in class..

• Right Triangle Trig Review

• Solving Right Triangles Guided Practice

• Summary

• Homework: Solving Right Triangles Trig Review (Goformative)

Multiple Choice

If I know the side lengths of two sides in a right triangle, I can find the length of the third side.

• True

• False

You can use the PYTHAGOREAN THEOREM to caclualte the missing side!

 $a^2+b^2=c^2$  

Multiple Choice

If I know one side length and one acute angle measure of a right triangle, I can find the other two side lengths.

• True

• False

Multiple Select

Looking at 20^o as the reference angle, which two sides are marked on this diagram?

• opposite

• adjacent

• hypotenuse

• right

• 70^o

Multiple Choice

Therefore, which trig ratio must we use?

• Sine

• Cosine

• Tangent

• Cotangent

Multiple Choice

Now that we know we have opposite and adjacent and will be using tangent to help us solve, which ratio is correctly set up?

• $\tan20=\frac{10}{x}$

• $\tan20=\frac{x}{10}$

• $\tan10=\frac{20}{x}$

• $\tan10=\frac{x}{20}$

• $\tan x=\frac{10}{20}$

Multiple Select

Looking at 40^o as the reference angle, which two sides are marked on this diagram?

• Opposite

• Adjacent

• Hypotenuse

• 40^o

• Pythagorean Theorem

Multiple Choice

Therefore, which trig ratio must we use?

• Sine

• Cosine

• Tangent

• Secant

Multiple Choice

Now that we know we have adjacent and hypotenuse and will be using cosine to help us solve, which ratio is correctly set up?

• $\cos40=\frac{1.7}{y}$

• $\cos40=\frac{y}{1.7}$

• $\cos1.7=\frac{\cos40}{y}$

• $\cos40=\frac{\cos1.7}{y}$

• $\cos1.7=40y$

Steps to solving for a missing side of a right triangle using trig:

• Identify which 2 sides are "given"

• Determine which trig ratio to use

• Set up an equation (proportion)

• Isolate the missing variable (solve)

• THEN, use a calculator

Homework

Solving Right Triangles Review (Goformative)

Video Embedded

Autogrades

Let's get started now!