Question

Calculate the area of the shaded region in two different ways. Explain the difference between your two methods.

Answer 1

• 20 unit²

Explanation:

Method 1

Area of trapezium

• A = 1/2(b1 + b2)h
• A = 1/2(3 + 7)(4) = 1/2(10)(4) = 20 unit²

Method 2

Area of rectangle - Area of triangle

• A = lw = 7*4 = 28 unit²
• A = 1/2bh = 1/2*4*4 = 8 unit²
• 28 - 8 = 20 unit²