Question

15. Scott and Tara were asked to find the

area of this trapezoid:
16 cm
18 cm
24 cm
Scott wrote A = 2(24 + 16)(8).
Tara wrote A = (16 + 24)(8)
Which student is correct? Explain.​

Answer 1

Both Scott and Tara have responded correctly.

Explanation:

we know that

The area of a trapezoid is equal to

A=(1/2)[b1+b2]h

we have

b1=16 cm

b2=24 cm

h=8 cm -----> Note The height is 8 cm instead of 18 cm

substitute

A=(1/2)[16+24](8)

A=160 cm²

Verify Scott 's work

Note Scott wrote A = (1/2)(24 + 16)(8) instead of A = 2(24 + 16)(8)

Remember that the Commutative Property establishes "The order of the addends does not alter its result"

so

(24+16)=(16+24)

A = (1/2)(24 + 16)(8)=160 cm²

Verify Tara's work

Note Tara wrote A = (1/2)(16+24)(8) instead of A = (16 + 24)(8)

A = (1/2)(16+24)(8)=160 cm²