Answer:
Option D. It's a perfect square trinomial.
Step-by-step explanation:
(a) 36x² - 4x + 16
= (6x)² - 2(2x) + (4)²
It's not a perfect square trinomial
(b) 16x² - 8x + 36
= (4x)² - 2x(4x) + (6)²
It's not a perfect square trinomial
(c) 25x² + 9x + 4
= (5x)² + 2
+ (2)²
It's not a perfect square trinomial
(d) 4x² + 20x + 25
= (2x)² + 2(10x) + (5)²
= (2x+5)²
It's a perfect square trinomial.
Sin75° = Sin(30° + 45°)
= Sin30°.Cos45° + Sin45°.Cos30°
= 1/2 . √2/2 + √2/2.√3/2
= √2/2 ( 1/2 + √3/2 )
= √2/2 ((1+√3 ) /2 )
= (√2 + √6 )/ 4
The amount of material/ number of pillows made
16/12 = 4/3 = 1 1/3
So the answer lies between integers 1 & 2