Answer:
Given: In parallelogram ABCD, AC=BD
To prove : Parallelogram ABCD is rectangle.
Proof : in △ACB and △BDA
AC=BD ∣ Given
AB=BA ∣ Common
BC=AD ∣ Opposite sides of the parallelogram ABCD
△ACB ≅△BDA∣SSS Rule
∴∠ABC=∠BAD...(1) CPCT
Again AD ∥ ∣ Opposite sides of parallelogram ABCD
AD ∥BC and the traversal AB intersects them.
∴∠BAD+∠ABC=180∘ ...(2) _ Sum of consecutive interior angles on the same side of the transversal is
180∘
From (1) and (2) ,
∠BAD=∠ABC=90∘
∴∠A=90∘ and ∠C=90∘
Parallelogram ABCD is a rectangle.
Answer:
StartFraction 16 over 81 EndFraction
Step-by-step explanation:
There are 4 prime numbers from 2 to 10 (2, 3, 5, 7) and 9 numbers from 2 - 10. Total possibilities: 9 * 9 = 81
Prime possibilities: 4 * 4 = 16
Therefore the answer is 16/81 or StartFraction 16 over 81 EndFraction
The first one is 154
The second one is 12.65^2
