Which equation correctly relates the measure of angle ${\theta }_1$ in a right triangle to the lengths of the opposite side $O$ and the hypotenuse $H$?

In a right triangle EFD, angle $F$ is the right angle, and the lengths of sides $EF$ and $FD$ are $3$ and $4$ units respectively. What is the measure of angle $EFD$ (in degrees)?

In a triangle, if one angle measures $130°$, which of the following statements is true about the triangle and its angles?

In a right triangle, if two triangles have their corresponding acute angles equal, which angles are congruent to each other?

If an angle in a right triangle measures $x$ degrees, what is the measure of its supplement?

Which of the following sets of measurements could represent the side lengths in feet of a right triangle?

In a right triangle, if $a$ and $c$ are the lengths of the leg and hypotenuse respectively, which of the following expressions represents $sin\theta$ where $\theta$ is the angle opposite side $a$?

Given that $\cos \left(\theta \right)$ = $\frac{3}{10}$, what is the value of $\sin \left(\theta \right)$ if $\theta$ is an acute angle?

Given a right triangle where the side opposite angle $\theta$ has length $3$, the adjacent side has length $4$, and the hypotenuse has length $5$, what is the equation for the trigonometric function $f\left(x\right)$ that represents $sin$ of angle $\theta$ in terms of these side lengths?