9 9-1 Developing Formulas for Triangles and Quadrilaterals Find each measurement. 1. the area of the rectangle
2. the area of the parallelogram 6.2 in.
x–5 2x + 3
4.2 in. 9.8 in.
2x 2 2 7x 2 15
41.16 in.2
3. the value of x when A
240 ft 2
4. the height of the trapezoid with A 110.5 m2 14 m
15 ft
h
x 20 m
8 ft
6.5 m
3. The geoboard shows a rectangle, a triangle and a trapezoid. Find the perimeter and area of each. rectangle: P 5 20; A 5 21 triangle: P 5 12; A 5 8 trapezoid: P 5 9 1 4Ï2 w 1 Ï17 w ø 18.8; A 5 18
9-2 Developing Formulas for Circles and Regular Polygons Find each measurement. 6. the circumference of (C in terms of p
