Report

7.4: Areas of Trapezoids, Rhombuses and Kites Objectives: •To find the area of a trapezoid, rhombus and kite. •To use right triangles in finding area of geometric figures TRAPEZOID b1 LEG LEG b2 The height (h) is the perpendicular distance between the bases b1 and b2 are the bases (the parallel sides) AREA OF A TRAPEZOID A 1 2 h b1 b 2 Find the area of the trapezoid: 12cm 7cm 15 cm Find the area: 14 in 8 in 20 in. Using Special Right Triangles to Find Area: 5m 60° 7m 1. Draw in height 2. Use special right triangle relationship to find height Find the area: 12 ft 45° 16 ft If the area of a trapezoid is 112 m2, and the lengths of the bases are 11 m and 21 m, what is the height? Area of a RHOMBUS or a KITE • Only one formula to know! It’s the same for both! Area = ½ the product of the lengths of the diagonals Area = 1 2 d1 d 2 or d1 d 2 2 PLEASE, PLEASE, PLEASE BE CAREFUL!!! IT IS THE PRODUCT OF THE DIAGONALS, NOT THE SUM!! RHOMBUS d1 d2 KITE d2 d1 Find the area of the kite: 1. 2. 3 2 3 5 4.5 10 2 4.5 Find the area of the Rhombus: What do we know about the diagonals of a rhombus? B 15 m E A 12 m D C Use the Pythagorean Theorem to find the length of BE: