Cross-Sections and Angle Relationships

The video tutorial covers slicing solids, focusing on identifying cross-sections of cubes and other 3D figures. It explains how to achieve specific cross-sections by slicing parallel or perpendicular to faces. The tutorial also addresses supplementary angles, providing examples and calculations. Lastly, it explores price calculation problems, demonstrating how to express price changes using percentages and algebraic expressions.

What shape is the cross-section when a cube is sliced through points A, B, and C?

• Triangle

• Rectangle

• Circle

• Hexagon

How would you slice a three-dimensional figure to get a cross-section that looks like a trapezoid?

• None of the above

• Parallel to a face

• Perpendicular to a face

• Diagonal to a face

To get a rectangular cross-section from a three-dimensional figure, how should you slice it?

• Perpendicular to a rectangular face

• Diagonal to a rectangular face

• Parallel to a rectangular face

• None of the above

What is the sum of two supplementary angles?

• 360 degrees

• 270 degrees

• 180 degrees

• 90 degrees

If one angle measures 80 degrees, what is the measure of its supplementary angle?

• 100 degrees

• 180 degrees

• 90 degrees

• 80 degrees

If the measure of an angle is X, how do you find the measure of its supplementary angle?

• X + 90

• 180 + X

• X - 90

• 180 - X

Two months ago, the price of a cell phone was C dollars. Last month, the price increased by 10%. What is the expression for the price last month?

• C - 10

• C + 10

• 0.9C

• 1.1C

This month, the price of the phone decreased by 10% from last month. What is the expression for the price this month?

• C + 0.1C

• 1.1C

• 0.99C

• C - 0.1C

Is the price of the phone this month the same as it was two months ago?

• No, it is cheaper

• Yes, it is the same

• No, it is more expensive

• It cannot be determined

Why is the phone cheaper this month compared to two months ago?

• Because 0.99C is less than C

• Because 1.1C is less than C

• Because 0.9C is less than C

• Because 1.01C is less than C