With this semicircle area calculator, you can quickly find the area of half of a circle. What is more, the tool also doubles as a semicircle perimeter calculator, so inputting radius or diameter will help you find the basic features of the shape in the blink of an eye. In the article below, we provide the semicircle definition and explain how to find the perimeter and area of a semicircle. So what are you waiting for? Scroll down! However, if you're searching for a moment of inertia of a semicircle, check out our comprehensive moment of inertia calculator.
A semicircle is simply half of a circle 🌗. You'll get a semicircle when you cut a circle along a diameter line - or, in other words, through the circle center. The prefix semi- comes from Latin, meaning half or partly (like in words such as semi-permanent, semi-formal, and semifinal). Now, when you know the etymology, you won't forget what a semicircle is: just remind yourself how the semifinals are connected with the finals, and you'll know how to link a semicircle to a circle.
Knowing the semicircle definition – half of a circle – we can easily write the semicircle area formula using the well-known circle area, π⋅r2\pi\cdot r^2π⋅r2: A_{\mathrm{semicircle}} = \frac{A_{\mathrm{circle}}{2} = \frac{\pi\cdot r^2}{2} The area of a semicircle is just half of the area of a full circle. But can we use this rule for the circumference of a semicircle?
If you want to calculate the outer boundary of a semicircle – the circumference or perimeter of a semicircle – you need to be careful not to fall into any traps. The circumference of a semicircle is not equal to half of the circle circumference - you need to add also the diameter of the semicircle, as another boundary was created: Psemicircle=Pcircle2+2⋅rP_{\mathrm{semicircle}} = \frac{P_{\mathrm{circle}}}{2} + 2\cdot rPsemicircle=2Pcircle+2⋅r Psemicircle=π⋅r+2⋅r=r⋅(π+2)P_{\mathrm{semicircle}} = \pi\cdot r + 2\cdot r = r\cdot (\pi+2)Psemicircle=π⋅r+2⋅r=r⋅(π+2) Psemicircle=π⋅r+dP_{\mathrm{semicircle}} = \pi\cdot r + dPsemicircle=π⋅r+d Where ddd is the semicircle diameter
Where do we find semicircular objects in everyday life? The shape of a half circle occurs in:
Let's figure out how to find an area of a semicircular object – a rug that would fit perfectly in front of your fireplace🔥:
Now, as you know everything about semicircles, maybe you'd like to check our other circle-related calculators 🔴? |