Explanation

Electromagnetic waves are transverse waves, meaning the oscillations of electric and magnetic fields are perpendicular to the direction of wave propagation.

Unlike mechanical waves, they do not need a medium and can travel through a vacuum.

Explanation

She had been sleeping for six hours when I woke her up.

The sentence is in past perfect continuous tense.

"Had been" is used to describe an action that started in the past and continued up to another point in the past.

Explanation

"Re-" is a prefix meaning "again" (e.g., rebuild, rewrite).

Prefixes are added at the beginning of words, unlike -ly or -ness, which are suffixes.

Explanation

"After that" is used to show the step just before the final one.

It helps transition smoothly toward the conclusion (which is marked by "Finally").

Explanation

A reflex angle is any angle greater than 180° but less than 360°.

215° fits this definition.

Explanation

The absolute value of a number is its distance from 0 on the number line, always positive.

So, |−13| = 13.

Explanation

"So far" is used to refer to something that has happened up until the present moment.

So far means اب تک

Explanation

Fractional distillation separates liquids based on differences in their boiling points.

It is commonly used for separating components in crude oil and alcohol purification.

Explanation

Explanation

Area of parallelogram = base × height = 16 × 9 = 144 cm²

Area of square = side² → side = √144 = 12 cm