Math Problem Statement

Find the area and circumference of two circles, the perimeter of an L-shaped figure, the surface area and volume of a rectangular prism, the volume of a triangular prism, the area of a composite shape, and the missing angle x in a triangle.

Solution

Let's go through each problem and solve them step by step.


1. Find the area and circumference of the circles:

  • Circle 1 (radius = 10 m):

    • Area: A=πr2=π×102=100πA = \pi r^2 = \pi \times 10^2 = 100\pi square meters.
    • Circumference: C=2πr=2π×10=20πC = 2\pi r = 2\pi \times 10 = 20\pi meters.
  • Circle 2 (radius = 8 m):

    • Area: A=πr2=π×82=64πA = \pi r^2 = \pi \times 8^2 = 64\pi square meters.
    • Circumference: C=2πr=2π×8=16πC = 2\pi r = 2\pi \times 8 = 16\pi meters.

2. Find the perimeter of the L-shaped figure:

The L-shaped figure has the following dimensions:

  • Vertical segments: 5 cm and 4 cm.
  • Horizontal segments: 4 cm and 2 cm.

We need to sum all the sides:

Perimeter=5+4+4+2=15cm\text{Perimeter} = 5 + 4 + 4 + 2 = 15 \, \text{cm}


3. Find the surface area and volume of the rectangular prism:

  • Dimensions: 7cm×5cm×3cm7 \, \text{cm} \times 5 \, \text{cm} \times 3 \, \text{cm}.

    • Surface area: The formula for surface area AA of a rectangular prism is: A=2(lw+lh+wh)A = 2(lw + lh + wh) where l=7cm,w=5cm,h=3cml = 7 \, \text{cm}, w = 5 \, \text{cm}, h = 3 \, \text{cm}.

      A=2(7×5+7×3+5×3)=2(35+21+15)=2×71=142cm2A = 2(7 \times 5 + 7 \times 3 + 5 \times 3) = 2(35 + 21 + 15) = 2 \times 71 = 142 \, \text{cm}^2

    • Volume: The volume VV of a rectangular prism is: V=l×w×h=7×5×3=105cm3V = l \times w \times h = 7 \times 5 \times 3 = 105 \, \text{cm}^3


4. Calculate the volume of the triangular prism:

The triangular prism has a triangular base with dimensions:

  • Base = 6 cm,
  • Height of triangle = 5 cm,
  • Length of prism = 20 cm.

The formula for the volume VV of a triangular prism is: V=12×base of triangle×height of triangle×lengthV = \frac{1}{2} \times \text{base of triangle} \times \text{height of triangle} \times \text{length} V=12×6×5×20=300cm3V = \frac{1}{2} \times 6 \times 5 \times 20 = 300 \, \text{cm}^3


5. Find the area of the shape:

This problem involves a composite shape made up of two rectangles. The dimensions given are:

  • Large rectangle: 11cm×14cm11 \, \text{cm} \times 14 \, \text{cm},
  • Small rectangle: 6cm×4cm6 \, \text{cm} \times 4 \, \text{cm}.

The total area is: A=(11×14)(6×4)=15424=130cm2A = (11 \times 14) - (6 \times 4) = 154 - 24 = 130 \, \text{cm}^2


6. Find xx in the triangle:

The given triangle has angles:

  • 4040^\circ,
  • 7070^\circ, and
  • xx^\circ.

Since the sum of angles in a triangle is 180180^\circ: x=180(40+70)=180110=70x = 180^\circ - (40^\circ + 70^\circ) = 180^\circ - 110^\circ = 70^\circ


Would you like more details or have any questions about these solutions?


Here are 5 related questions to explore further:

  1. How do you calculate the area of a sector of a circle?
  2. Can you find the volume of a cone given its height and radius?
  3. How would you calculate the surface area of a sphere?
  4. What is the difference between perimeter and circumference?
  5. How do you find the height of a triangle if only the base and area are known?

Tip: Always keep in mind the correct units when solving geometry problems. For areas, it's squared units, and for volume, it's cubed units!

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Math Problem Analysis

Mathematical Concepts

Geometry
Area
Perimeter
Circumference
Surface Area
Volume
Triangle Angle Sum Theorem

Formulas

Area of a circle: A = πr²
Circumference of a circle: C = 2πr
Perimeter of a shape: Sum of all sides
Surface area of a rectangular prism: A = 2(lw + lh + wh)
Volume of a rectangular prism: V = l × w × h
Volume of a triangular prism: V = 1/2 × base × height × length
Sum of angles in a triangle: 180°

Theorems

Triangle Angle Sum Theorem

Suitable Grade Level

Grades 6-9