The answer is D.
This figure has 4 sides which makes it a quadrilateral.
This figure has 2 sets of parallel sides which makes it a parallelogram.
This figure has 4 equal sides which makes it a rhombus.
This figure has 4 right angles which makes it a rectangle.
And this figure has both 4 equal sides and 4 equal angles which makes it a square.
To make it easier, all squares are: quadrilaterals, parallelograms, rhombuses, rectangles and of course squares.
Answer:
a=5
Step-by-step explanation:
a^2+b^2=c^2
c^2-b^2=a^2
13^2-12^2=a^2
169-144=a^2
25=a^2
5=a