This answer uses trigonometry to avoid a lot of work:tangent = opposite/adjacent and tangent*adjacent (base of ladder from the building) = opposite (height of ladder above ground)So: tangent 60 degrees*3 = 5.196152423Therefore: Top of the ladder above ground = 5.2 meters correct to one decimal place.More laborious methodThe right triangle formed by the wall, ground and ladder has sides in the ratio of 1::2::sq-rt-of-3. The shortest side is the one opposite the 30 degree angle, i.e., the given distance from wall to base of the ladder--3 m.The length of the ladder represents the hypotenuse of the triangle, and is twice as long, hence 6 m.And the height of the ladder's top from the ground is proportional to the third side whose length is sq-rt-3 times that of the shortest side. Sq-rt-3 is about 1.732, so height of the ladder's top at the wall is about 5.20 m, or 520 cm.
The ladder forms a right angle with the building: the ground and the building forming the right angle and the ladder forming the hypotenuse. If the length of the ladder is L metres, then sin(49) = 12/L So L = 12/sin(49) = 15.9 = 16 metres.
below, it looks better
This describes a right triangle. This triangle has a base (X ) of 3 ft, a opposite side ( Y) of 9 ft. So, you are looking for the hypothenuse. Use the Pythagoreum theory. In this case. Your ladder length is called H. H^2 = X^2 + Y^2 H = sqrt X^2 + Y^2
its 45 degree
1 metres
A straight ladder should extend at least 3 feet above the work surface or landing for safe access to and from the ladder. This helps provide stability and a secure handhold when climbing up or down.
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From the US OSHA Construction standards:1926.1053(b)(1)When portable ladders are used for access to an upper landing surface, the ladder side rails shall extend at least 3 feet (.9 m) above the upper landing surface to which the ladder is used to gain access; or, when such an extension is not possible because of the ladder's length, then the ladder shall be secured at its top to a rigid support that will not deflect, and a grasping device, such as a grabrail, shall be provided to assist employees in mounting and dismounting the ladder. In no case shall the extension be such that ladder deflection under a load would, by itself, cause the ladder to slip off its support.
Assuming it is a two section ladder then it must therefore have a minimum length of 28 feet.
Because someone may be working on it above you, and they could drop something, or, the ladder could fall.
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a modern military trench should be 2 inches above the tallest mans head. So if you 5 foot exactly u need a 5 foot 2 inch trench.
The world's largest trench is the marina trench which is found right above japan.
To safely access the roof using a ladder extension, make sure the ladder is long enough to reach the roof and is securely placed on a stable surface. Extend the ladder at least 3 feet above the roof edge for stability. Use proper ladder safety techniques, such as maintaining three points of contact and facing the ladder while climbing. Have someone hold the ladder at the base for added stability.
To safely put a ladder on a sloped roof, use a ladder stabilizer or standoff to keep the ladder stable and prevent it from slipping. Make sure the ladder is long enough to extend at least 3 feet above the roof edge for proper support. Position the ladder at the correct angle, with the base of the ladder 1 foot away from the wall for every 4 feet of ladder height. Always have someone hold the ladder while you climb for added safety.
ALWAYS use a ladder or step-stool