← Checkpoint Mathematics
Circumference and area of circles · 6 left
This one needs a free account (about 20 seconds, no card). You'll land straight back on it.
Quick drill · instant marking
Try it free — the AI marks 3 answers a day. A free account marks 30 a day.
Sign up free →
A circle has a radius of 4 cm. Taking \(\pi\) as 3, work out an estimate of its area in cm².
💡 Need a nudge?
Which formula gives the area of a circle, and which length goes into it?
[1 mark]
Type
Photo · Sign up
Write · Sign up
⌨ Math input
▾
Hide phone keyboard
Your answer
a⁄b
√
x²
x^
log
ln
∛
|x|
π
°
(
)
sin
cos
tan
sin⁻¹
cos⁻¹
tan⁻¹
7
8
9
⌫
AC
◀
4
5
6
×
÷
▶
1
2
3
+
−
=
0
.
×10ⁿ
Ans
,
%
More symbols
▾
<
>
≤
≥
%
≈
eˣ
10ˣ
n!
∞
≠
±
Σ
∫
d/dx
ⁿCᵣ
ⁿPᵣ
→
[ ]
{ }
i
j
e
a b⁄c
∩
∪
′
∅
⊂
∈
✎ Switch to equation editor
beta
Loading…
📷 Tap to photograph your answer
Calculation — marked on the value.
Check answer →
🧭
Modelled on Cambridge Checkpoint 0862 · Apr/May 2026 · Paper 1 · Q3
Stuck? Get a hint
Free
Guided Hint
— no answers, just a nudge
Close ✕
Thinking
.
.
.
One more nudge →
Let me try now
Find this hard? There are simpler questions on this skill
Circle: circumference and area, and the reverse
10 quick questions · about 45 s each · checked instantly · no account needed →
Worked solution
Show all steps
That's the full method. Now try one like it yourself.