The 3-4-5 triangle is a great way to make sure the corners are square and the panels at a 90-degree angle (see Figure 1, top). If one side of a triangle measures 3 feet and the adjacent side measures ...

A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. The dashes on the lines show they are equal in length.

Since there are 5 triangles, the sum of the angles inside the shape is 5 × 180 = 900 ∘ b) The shape is a regular heptagon, so all the angles must be equal. The total of all 7 equal angles is ...