# ACT Math : Trigonometry

## Example Questions

### Example Question #1 : Tangent

What is the tangent of C in the given right triangle??

Explanation:

### Example Question #1 : Tangent

Consider a right triangle with an inner angle .

If

and

what is ?

Explanation:

The tangent of an angle x is defined as

Substituting the given values for cos x and sin x, we get

### Example Question #2914 : Act Math

Triangle ABC shown is a right triangle. If the tangent of angle C is , what is the length of segment BC?

Explanation:

Use the definition of the tangent and plug in the values given:

tangent C = Opposite / Adjacent = AB / BC = 3 / 7

Therefore, BC = 7.

### Example Question #1 : How To Find The Tangent Of An Angle

If the sine of an angle equals , and the cosine of the same angle equals , what is the tangent of the angle?

Explanation:

The cosine of the angle is  and since that is a reduced fraction, we know the hypotenuse is  and the adjacent side equals .

The sine of the angle equals , and since the hyptenuse is already  we know that we must multiply the numerator and denominator by  to get the common denominator of .  Therefore, the opposite side equals .

### Example Question #1 : How To Find An Angle With Tangent

For the above triangle,  and . Find .

This triangle cannot exist.

Explanation:

With right triangles, we can use SOH CAH TOA to solve for unknown side lengths and angles. For this problem, we are given the opposite and adjacent sides of the triangle with relation to the angle. With this information, we can use the tangent function to find the angle.

### Example Question #2 : How To Find An Angle With Tangent

In the above triangle,  and . Find .

Explanation:

With right triangles, we can use SOH CAH TOA to solve for unknown side lengths and angles. For this problem, we are given the opposite and adjacent sides of the triangle with relation to the angle. With this information, we can use the tangent function to find the angle.

### Example Question #3 : How To Find An Angle With Tangent

For the above triangle,  and . Find .

This triangle cannot exist.

Explanation:

With right triangles, we can use SOH CAH TOA to solve for unknown side lengths and angles. For this problem, we are given the opposite and adjacent sides of the triangle with relation to the angle. With this information, we can use the tangent function to find the angle.

### Example Question #4 : How To Find An Angle With Tangent

A laser is placed at a distance of  from the base of a building that is  tall. What is the angle of the laser (presuming that it is at ground level) in order that it point at the top of the building?

Explanation:

You can draw your scenario using the following right triangle:

Recall that the tangent of an angle is equal to the ratio of the opposite side to the adjacent side of the triangle. You can solve for the angle by using an inverse tangent function:

or .

### Example Question #5 : How To Find An Angle With Tangent

What is the value of  in the right triangle above? Round to the nearest hundredth of a degree.

Explanation:

Recall that the tangent of an angle is equal to the ratio of the opposite side to the adjacent side of the triangle. You can solve for the angle by using an inverse tangent function:

or .

### Example Question #1 : Trigonometry

For the triangles in the figure given, which of the following is closest to the length of line NO?

7

6

10

9

8