# What is the length of a shadow at 8am?

• korko
In summary, the conversation is about finding the length of a shadow of a building at 8AM using the angle of the sun and its apparent motion across the sky. The sun rises at 6AM and sets at 6PM, covering 180 degrees in 12 hours. By looking at the angle and fraction of time passed since sunrise, the length of the shadow can be determined.
korko
Hi there!

I need help with trig. I know how to find angles or sides etc. but the problem is I can't picture what this word problem trying to ask me. It would be great if you show me the picture, and I would most likely know how to figure out the sides.

Q1:
On a sunny day, the shadows of stationary objects move slowly across the ground. This is caused by the apparent motion of the sun across the sky, due to the rotation of the Earth. Assume that the sun rises due east at 6a.m, and sets due west at 6p.m.

Find the length of the shadow of a 150m building at:
a) 8A.M

Thanks,

Look at it in terms of angles and fractions. The sun has 180 degrees to cover over a period of 12 hours. 8am is 2 hours after sunrise. The angle of the sun is related to the angel of the shadow.

Last edited:
kts123 said:
Look at it in terms of angles and fractions. The sun has 180 degrees to cover over a period of 12 hours. 8am is 2 hours after sunrise. The angle of the sun is related to the angel of the shadow.

yes it does, thank you! :D

## 1. How do I find the measure of an angle?

To find the measure of an angle, you will need to use a protractor. Place the center of the protractor on the vertex of the angle and align one side of the protractor with one side of the angle. Read the number on the protractor where the other side of the angle intersects. This is the measure of the angle in degrees.

## 2. How do I find the missing angle in a triangle?

To find the missing angle in a triangle, you will need to use the triangle angle sum theorem. This theorem states that the sum of the interior angles of a triangle is always 180 degrees. So, if you know the measure of two angles in a triangle, you can subtract their sum from 180 to find the measure of the missing angle.

## 3. How do I find the length of a side in a right triangle?

To find the length of a side in a right triangle, you can use the Pythagorean theorem. This theorem states that in a right triangle, the square of the length of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. So, if you know the lengths of any two sides in a right triangle, you can use the Pythagorean theorem to find the length of the third side.

## 4. How do I find the measure of an angle using trigonometry?

To find the measure of an angle using trigonometry, you will need to know the lengths of two sides of a right triangle. You can then use one of the trigonometric functions (sine, cosine, or tangent) to calculate the measure of the angle. For example, if you know the length of the opposite side and the adjacent side, you can use the tangent function to find the measure of the angle.

## 5. How do I find the angle of elevation or depression?

To find the angle of elevation or depression, you will need to use basic trigonometry and the information given in the problem. The angle of elevation is the angle between the horizontal and the line of sight when looking up at an object, while the angle of depression is the angle between the horizontal and the line of sight when looking down at an object. You can use the tangent function to find these angles by dividing the opposite side (height) by the adjacent side (distance).

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