Work out the length of am, then find the area of the triangle.
* refer to image below*

see explanation

Step-by-step explanation:

ΔABC is isosceles and AM is the perpendicular bisector to BC, hence

BM = MC = 4 cm

Using Pythagoras' identity on ΔABM, then

AB² = AM² + BM², that is

7² = AM² + 4²

49 = AM² + 16 ( subtract 16 from both sides )

33 = AM² ( take the square root of both sides )

AM =

The area (A) of ΔABC is found using

A = bh ( b is the base BC and h the height AM )

A = × 8 × = 4 cm² ≈ 23 cm²

pentagon

step-by-step explanation:

the coordinates   a(5, -2), b(3,-1),c(-4,-4) d(-3,8) and e(-1,4) forms the vertices of the polygon when they are connected in order.

in order to classify that which polygon is it with the given coordinates, first count the number of vertices and then count the number of sides it can make with these vertices.

since, the given coordinates have five vertices, therefore, it will make five sides. moreover, pentagon is regular in nature therefore it will be convex.

now, a polygon with five sides is known as pentagon, therefore, the given polygon is the pentagon.

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons