Question

Please help me with this question. Tell me how you work it out.

Answer 1

D

Explanation:

the shaded part of the rectangle is a triangle

the area (A) of a triangle is calculated as

A =
`(1)/(2)` bh ( b is the base and h the perpendicular height )

the opposite sides of the rectangle are congruent (equal), both 12 cm

then the base of the triangle = 12 - 6 = 6 cm

so b = 6 and h = 6 , then

A =
`(1)/(2)` × 6 × 6 = 3 × 6 = 18 cm²