Write out the sum formula for sin
<span>sin(x + y) = sinxcos + sinycosx </span>
<span>Then expand sin(a + b) + sin(a - b) </span>
<span>sinacosb + sinbcosa + sinacosb - sinbcosa </span>
<span>The 2nd and 4th terms cancel and you get </span>
<span>2sinacosb</span>
Answer:
27 days
Step-by-step explanation:
20 
÷ 
= 27
Its impossible to draw a trapezoid with just three right angles.
a trapezoid has 4 sides, which means all the angles inside the trapezoid must add up to 360 degrees.
if you have just 3 right angles (90x3), you already use up 270 degrees. Leaving you with just 90 degrees left, which is also a right angle. That means, there has to be four, if you have at least 3.
Answer:
Step-by-step explanation:
Given that,
Radius of a cone, r = 13 cm
Slant height of the cone, l = 20 cm
We need to find the surface area of the cone. The formula for the surface area of the cone is given by :
Put all the values,
So, the surface area of the cone is 
.
