Find a strategy to make each calculation mentally:
[math]599+87[/math]
[math]254-88[/math]
[math]99\cdot75[/math]
Here is a floor plan of a house. Approximate lengths of the walls are given.
What is the approximate area of the home, including the balcony? Explain or show your reasoning.
The two triangles are equilateral, and the three pink regions are identical. The blue equilateral triangle has the same area as the three pink regions taken together.
What is the ratio of the sides of the two equilateral triangles?