Answer:
1. A = 40 units²
2. A = 72 units²
3. B) 45
Explanation:
1. This shape comprises 4 congruent triangles with base of 5 units and height of 5 units.
Area of a triangle = 1/2 x base x height
Therefore, area of polygon = 4(1/2 x 5 x 4)
= 40 units²
2. This shape comprises two pairs of congruent triangles.
Area of a triangle = 1/2 x base x height
Therefore, area of polygon = 2(1/2 x 2 x 6) + 2(1/2 x 10 x 6)
= 72 units²
3. Count the number of shaded squares:
9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = 45 units²