Anyone any good at trigonometry?

Question

If you are, can you help me with the following question please?

I have a right-angled triangle. The hypotenuse is 19 cm. The opposite length is 13 cm. I need to find the missing angle. How do I do it? Thanks!

Answer 1

Opposite angle or side? Which angle would you need (opposite, adjacent, hypotenuse)?

I can tell you the missing length of the other side of the triangle:

Use the Pythagorean Theorem:

aˆ2 + bˆ2 = cˆ2, where cˆ2 is the hypotenuse.

Substitute. Let a = 13, b = the missing side and c = 19

(13)ˆ2 + bˆ2 = (19)ˆ2

169 + bˆ2 = 361

bˆ2 = 192

b = √192

b = 13.86

-----------------------------------

If what you're looking for is the opposite angle, you can use

Sin-1(13/19)

43.17 degrees

Hope I helped!

Answer 2

The missing angle or side? The missing side is sqrt(19^2-13^2)

Maybe use the law of sines with whatever angles you have?

SinA/a = SinB/b

Or if you are talking about the angle that is opposite the opposite side:

Sin-1(13/19) =43.17 degrees

Answer 3

There is some confusion as to THE missing angle.

There are 2 missing angles, one, call angle A is between the hyp-19 and side-13

angle A = arccos (13/19) = 46.83 degrees

The other (complementary) angle is opposite side-13 and is

arcsin (13/19) = 43.17 degrees.

-----------
Finally, the missing (one) side can come from the Pythagorean theorem. Its length is sqrt(192) = 13.85

Answer 4

Use sin(angle) = 13 / 19

Answer 5

with a right triangle you can do opposite over hypot = sin alpha. that gives you an angle of 43.17 degrees

180-90-43.17 would give you the last angle inside the triangle

Answer 6

Sin θ=opposite/hypotenuse

Sin θ=13cm/19cm

Sin θ= 0.6842

θ= Sinˉ¹ (0.6842)

θ= 43.17°≈ 43.2°