Geometry with right triangles

Question

I have this

How do I find $h$? I know that I must use the cosine of $70$ degrees but I'm not sure how.

Is it a sector? Is the triangle a right triangle? – mathlove Nov 03 '15 at 16:33 — mathlove, Nov 03 '15 at 16:33

Emilio Novati · Answer 1 · 2015-11-03T17:44:32.493

0

Hint:

If the center of the arc is in the right angle you have: $$ \dfrac{L-h}{h}=\tan 70° $$

that we you can solve for $h$.

If the center of the arc is in the $70°$ angle you have: $$ h=L\cos 70° $$ because the right triangle has hypotenuse $L$ and $h$ is the adiacent side to angle of $70°$.

edited Nov 03 '15 at 17:44

answered Nov 03 '15 at 16:37

Emilio Novati

62,675

Here is the answer that it gives h=cos x * L – Nov 03 '15 at 16:50
So, I've not well interpreted the figure. I change the ansewer :) – Emilio Novati Nov 03 '15 at 16:55
Sorry but could you draw me a picture... I dont understand – Nov 03 '15 at 17:03

mathlove · Accepted Answer · 2015-11-03T17:07:46.093

0

If it is a sector, then we know that the length of the hypotenuse of the right triangle is $L$, so we have $$h=L\cos70^\circ.$$

$\qquad\qquad\qquad$

edited Nov 03 '15 at 17:07

answered Nov 03 '15 at 16:52

mathlove

139,939

Could you draw me some quick image... Im not sure how to interpret it myself to be honest – Nov 03 '15 at 16:55
@Astroman: Does that help? – mathlove Nov 03 '15 at 17:08

Geometry with right triangles

2 Answers2