Sketch the triangle with vertices at the orgin O, P=(5,4,0), and Q=(2,1,4), and compute its area using cross products.

Consider noncoplanar points A, B, C, and D. Using three points at a time such as A, B, and C, how many planes are determined by these points?

Suppose a circle of radius r is inscribed in a rhombus, each of whose sides has length s. Find an expression for the area of the rhombus in terms of r and s.

The center of a circle of radius 2 inches is at a distance of 10 inches from the center of a circle of radius length 3 inches. To the nearest tenth of an inch, what is the approximate length of a common internal tangent? Use the hint provided in Exercise 38. HINT: use similar triangles to find OD and DP. Then apply the Pythagorean Theorem twice.

When the diagonals of rhombus MNPQ are drawn, how do the areas of the four resulting smaller triangles compare to each other and to the area of the given rhombus? Exercise 46

use the map in Figure 11.2. a Find the grid section of Taylor Hall. b. What is located in section 3B?