Chapter 1 - Tools of Geometry - 1-8 Perimeter, Circumference, and Area - Practice and Problem-Solving Exercises - Page 66: 45

$27\ in^2$

Find the area of the larger triangle and deduct the area of the smaller, unshaded triangle, to find the shaded area. $A_1=\frac{1}{2}bh=\frac{1}{2}(10)(6)=(5)(6)=30$ $A_2=\frac{1}{2}bh=\frac{1}{2}(3)(2)=(1.5)(2)=3$ $A=A_1-A_2=30-3=27$