Find the surface area and volume of the following figure. (1) the height of a rectangle is 20cm, the length is 15cm, and the width is 10cm

Find the surface area and volume of the following figure. (1) the height of a rectangle is 20cm, the length is 15cm, and the width is 10cm

Surface area formula of cuboid: (L × W + L × H + W × h) × 2
=(15×10+20×10+15×20)×2
=450×2
=900
Cuboid volume method is: length × width × height
=20×15×10
=3000
It's easier to read in this way. I hope it helps you

The radius of the inner circle is 10cm and the radius of the outer circle is 20cm. Calculate the area of the ring

Area of ring:
3.14×（20²-10²）
=3.14×300
=942 (square centimeter)

If the outer radius of a ring is 30cm and the inner radius is 10cm, the area of the ring is

Circle area = outer circle area - inner circle area = 30 & sup2; π - 10 & sup2; π = 800 π (CM & sup2;)