The correct option is A True
To prove: Ratio of the areas of two triangles of the same bases is equal to the ratio of their heights.
Proof:
Let us take triangle T1 with height h1 and base b1 and Triangle T2 with height h2 and base b2.
Area of Triangle T1 =12×base×height=12×b1×h1
Area of Triangle T2 =12×base×height=12×b2×h2
Ratio of area of two triangles,
Area of triangle T1 Area of triangle T2=12×b1×h112×b2×h2
=h1h2 (Base of two triangles are equal. So, b1=b2)
Proved.