An equilateral triangle’s angles each have a measure of 60 degrees.

1. Can you put copies of an equilateral triangle together to form a straight angle? Explain or show your reasoning.

2. Can you put copies of an equilateral triangle together to form a right angle? Explain or show your reasoning.

Here are two different patterns made out of the same five identical isosceles triangles. Without using a protractor, determine the measures of Angles  and . Explain or show your reasoning.

First diagram, a regular pentagon, segments from the center to eact vertex form 5 identical circles.  Each of the middle angles is colored blue and labeled x, the angles of the triangles around the perimeter are colored yellow and labeled y.  For the second diagram, the triangles from the first diagram have been rearranged so that the center is blue, yellow, yellow, x, yellow.  The 5 triangles do not rearrange to make a complete convex polygon, but the angles y, y, and x together form a straight angle.

The height of the water in a tank decreases by 3.5 cm each day. When the tank is full, the water is 10 m deep. The water tank needs to be refilled when the water height drops below 4 m.

1. Write a question that could be answered by solving the equation .
2. Is 100 a solution of ? Write a question that solving this problem could answer.

Use the distributive property to write an expression that is equivalent to each given expression.

Lin’s puppy is gaining weight at a rate of 0.125 pounds per day.  Describe the weight gain in days per pound.