Here's the question you clicked on:
Dallasb22
Find the area of the Trapezoid?
|dw:1348069206419:dw| do you know how to find x?
Actually i am brain frozen and cannot remember the formula. Can you tell me the formula please?
The formula for tan x is opp/adj. The formula for finding the area of a trapezoid is ((upper length + lower length) * height)/2.
Finding X in his above drawing would give me the height so i could than find the area.
But I do not remember how to find it. I have never used tan or sin before.
|dw:1348069912936:dw|
Were you taught trigonometry (sin, cos, tan) in your math lessons?
I am only in Geometry, so not yet.
This question involves trigonometry... I will just give you a crash course. For the triangle |dw:1348070256213:dw| (do notice that these formulas only work on triangles with a right angle), we pick a angle that is not the right angle itself. This time, I pick <AC. (answers continued since I can't see what I just drew)
uh... I meant <C. Anyways, we usually represent angles with the symbol theta (\(\theta\)). Remember these properties: (all of these are lengths of the said line) sin \(\theta\) = opposite/hypotenuse (sine) cos \(\theta\) = adjacent/hypotenuse (cosine) tan \(\theta\) = opposite/adjacent (tangent) What is opposite and what is adjacent in here? Notice that the angle <C is opposite of the line AB, so that is the opposite line. The <C is adjacent (or in other terms "sticks") to the line BC, so that's the adjacent. Let's look back at the question bit @Igbasallote asked you to solve. Here, tan\(\theta\) = x/3 (opposite/adjacent). Multiply both sides by 3, and get 3 tan\(\theta\) = x. It also specified that the angle is 60 degrees. I'll give you the answer here: tan 60degrees = \(\sqrt{3}\). Now multiply the answer by 3, and the answer becomes \(3\sqrt{3}\). Congrats, you just learnt pieces your classmates might've never learned. However, I suggest telling your teacher that you haven't learned trigonometry yet so he/she will not give you these kind of questions.
(Just that if you're curious how I pulled tan 60degrees out of the air, 60 degrees is actually a special angle. You can find the values of trigonometry function on special angles here: http://www.mathwords.com/t/trig_values_of_special_angles.htm )
Okay i think i got it. Yes i know the triangle ratio 30-60-90