What is the area of the shaded region?

Area of large triangle
= 1/2 bh
= 1/2 (5)(12) 
= 1/2 (60)
= 30

area of un-shaded triangle
= 1/2bh
= 1/2(3)(4)
= 1/2 (12)
= 6

area of shaded = area of large triangle  - area of un-shaded triangle
area of shaded = 30 - 6
area of shaded = 24

answer
24