Answer:
40
Step-by-step explanation:
180 degrees for a triangle. We add 87 and 53 degrees.
That equals 140. Again, back to 180 degrees. We minus 180 degrees with 140 degrees which equals:
40 degrees.
9514 1404 393
Answer:
(c) -3/4
Step-by-step explanation:
Subtracting a positive number moves you to the left on the number line. Subtracting a negative number moves you in the opposite direction, to the right.
Here, we start at -2 1/2 = -5/2, and we move 1 3/4 = 7/4 to the right from there. Each mark on this number line is 1/4 unit, so we move 7 marks. The results is ...
-2 1/2 -(-1 3/4) = -5/2 +7/4
= -10/4 +7/4 = -3/4
Answer:
Step-by-step explanation:
a) Pythagorean theorem,
altitude² + base² = hypotenuse²
h² + (w² - 1)² = (w² + 1)²
h² = (w² + 1)² - (w² - 1)²
{Compare with (a + b)² - (a -b)² = 4ab where a =w² & b = 1}
h² = 4*w²*1
h² = 4w²

b) Area of triangle = 

c) w =2
Area of triangle = 3w = 3*2 = 6
Sin (A + B) = sin A cos B + cos A Sin B
<span>Cos (A - B) = cos A cos B + sin A sin B </span>
<span>=> (SinACosB+ CosASinB) (CosACosB +SinASinB) </span>
<span>=>SinACosACos^2B+Sin^2ACosBSinB+Cos^2A... </span>
<span>=>SinACosA(Cos^2B+Sin^2B) +SinBCosB(Sin^2A+Cos^2A) </span>
<span>we know that Sin^2+Cos^2=1 </span>
<span>=>SinACosA(1)+SinBCosB(1) </span>
<span>=SinACosA+SinBCosB </span>
<span>Proved
</span>