Explanation

The centroid of a right-angled triangle lies 1/3 the base from the right angle along the base.

It divides the median in a 2:1 ratio from the vertex to the midpoint of the opposite side.

Explanation

Centering is the temporary framework used to support arches, domes, or other roof structures during construction.

It holds the structure in place until it becomes self-supporting.

Explanation

Straight stairs provide the easiest and most direct path, making them comfortable to use.

They are simple to construct and safe, with uniform steps and no tight turns.

Explanation

Sewage is mostly water, with about 90% of its content being water.

The remaining 10% consists of organic and inorganic solids, microorganisms, and other impurities.

Explanation

Declination is the angle between the geographic (true) north and magnetic north.

It helps in correcting compass readings for accurate navigation and surveying.

Explanation

A Gunter’s chain is a measuring device used in surveying, traditionally 66 feet long.

It is divided into 100 links, each 0.66 ft, for easy land measurement.

Explanation

Hooke’s law states that within the elastic limit, stress is directly proportional to strain.

It is the fundamental law describing elasticity in materials.

Explanation

A rowlock is a brick laid on its long edge with the short end (header) visible on the wall face.

It is commonly used for wall capping, sills, or decorative features.

Explanation

A metal lath is a steel mesh that provides a strong base for plaster or stucco to adhere to.

It helps in preventing cracks and ensures uniform application of plaster.

Explanation

Strain = Change in length / Original length

= 3 mm / 3000 mm

= 0.003 / 3

= 0.001