Hello from MrBillDoesMath!
Answer:
3 1/2 (i.e 3.5)
Discussion:
From the attached file, the area of the shaded triangle =
Area = square surrounding triangle -
area triangle 1 - area triangle 2 - area triangle 3
= 4 * 4 -
(1/2) (1 * 1) - (1/2) (3 * 4) - (1/2) (3 * 4)
= 16 - 1/2 - 1/2 (12) - 1/2(12) =
= 16 - 1/2 - 12 =
= 4 - 1/2
= 3 1/2
Where we have used that the area of a triangle =
(1/2) base * height.
Thank you,
MrB
