diff --git a/chapters/whatis/content.en-GB.md b/chapters/whatis/content.en-GB.md
index 9960c8d7..cec48a08 100644
--- a/chapters/whatis/content.en-GB.md
+++ b/chapters/whatis/content.en-GB.md
@@ -21,9 +21,9 @@ Given \left (
 
 So let's look at that in action: the following graphic is interactive in that you can use your up and down arrow keys to increase or decrease the interpolation ratio, to see what happens. We start with three points, which gives us two lines. Linear interpolation over those lines gives us two points, between which we can again perform linear interpolation, yielding a single point. And that point —and all points we can form in this way for all ratios taken together— form our Bézier curve:
 
-<graphics-element title="Linear Interpolation leading to Bézier curves" width="900" height="300" src="./chapters/whatis/interpolation.js">
+<graphics-element title="Linear Interpolation leading to Bézier curves" width="825" height="275" src="./chapters/whatis/interpolation.js">
   <fallback-image>
-    <img src="./chapters/whatis/interpolation.png" width="900" height="300">
+    <img src="./chapters/whatis/interpolation.png" width="825" height="275">
     {{ disableMessage }}
   </fallback-image>
 </graphics-element>
diff --git a/chapters/whatis/interpolation.js b/chapters/whatis/interpolation.js
index 6451ef8c..745fc161 100644
--- a/chapters/whatis/interpolation.js
+++ b/chapters/whatis/interpolation.js
@@ -1,6 +1,6 @@
 setup() {
     this.step = 25;
-    this.curve = Bezier.create(this, 70,250,  20,110,  250,60);
+    this.curve = Bezier.defaultQuadratic(this);
     setMovable(this.curve.points);
 }
 
diff --git a/index.html b/index.html
index ca007bcf..1ffd90cb 100644
--- a/index.html
+++ b/index.html
@@ -340,15 +340,15 @@
           </p>
           <graphics-element
             title="Linear Interpolation leading to Bézier curves"
-            width="900"
-            height="300"
+            width="825"
+            height="275"
             src="./chapters/whatis/interpolation.js"
           >
             <fallback-image>
               <img
                 src="./chapters/whatis/interpolation.png"
-                width="900"
-                height="300"
+                width="825"
+                height="275"
               />
               <span>Scripts are disabled. Showing fallback image.</span>
             </fallback-image>
diff --git a/ja-JP/index.html b/ja-JP/index.html
index 863eb95c..025d8854 100644
--- a/ja-JP/index.html
+++ b/ja-JP/index.html
@@ -254,15 +254,15 @@
           </p>
           <graphics-element
             title="Linear Interpolation leading to Bézier curves"
-            width="900"
-            height="300"
+            width="825"
+            height="275"
             src="./chapters/whatis/interpolation.js"
           >
             <fallback-image>
               <img
                 src="./chapters/whatis/interpolation.png"
-                width="900"
-                height="300"
+                width="825"
+                height="275"
               />
               <span>JSがなくて、画像を表示しています。</span>
             </fallback-image>
diff --git a/zh-CN/index.html b/zh-CN/index.html
index 589229b9..4798cd90 100644
--- a/zh-CN/index.html
+++ b/zh-CN/index.html
@@ -240,15 +240,15 @@
           </p>
           <graphics-element
             title="Linear Interpolation leading to Bézier curves"
-            width="900"
-            height="300"
+            width="825"
+            height="275"
             src="./chapters/whatis/interpolation.js"
           >
             <fallback-image>
               <img
                 src="./chapters/whatis/interpolation.png"
-                width="900"
-                height="300"
+                width="825"
+                height="275"
               />
               <span>脚本已禁用，并显示后备图像。</span>
             </fallback-image>